At Raw Garden, we have a ‘Farming First’ philosophy because we understand that the process of farming is the process of managing the plant’s life and the management of the land those plants grow on – this is when the plantgets its chance to thrive but requires that it is properly nurtured in order to provide resources such as high-quality terpenes and cannabinoids.
Our cannabis plants are sun-grown in Santa Barbara county soil just like other California crops. From the seed to the shelf, we are vertically integrated and maintain quality control at every step in the process. We grow our own seeds, farm and harvest our own plants, and process our own products while employing sustainable and regenerative farming practices – only organic and natural fertilizers, soil amendments and pest control methods are used on thefarm.
As farmers we have a responsibility to care for the land and the soil to ensure it is fertile and healthy well into the future. We take care of the soil and it takes care of our plants. The result is premium quality products that our customers love and trust. Our success and commitment to quality is proof that the economics of clean, sustainable operations are achievable. We’re farmers and scientists on a mission to make clean, high quality cannabis that is affordable and accessible.
A few of the sustainable agriculture practices we employ at Raw Garden include:
Clean Green Certification – Since our inception, we have been certified and licensed members of Clean Green, the #1 globally-recognized organic and sustainable cannabis certification program. The program was created in 2004 as a way to standardize legal cannabis products and the result was a program to help farms and brands obtain organic-like certification based on the USDA National Organic program. Clean Green-certified growers and processors regularly win awards for their high-quality products, including our award-winning extracts.
Water Conservation – Our farm team waters at the right time of day to reduce evaporative water loss; we also use drip irrigation and mulch to reduce water waste and runoff. Last year, we used about 8,000 gallons of water per acre on average, which is significantly less than standard outdoor grown crops.
Natural Fertilizer and Pest Control – We apply only organic fertilizers and foliar feeds and we spray only organic pathogen-free inoculants to keep our plants healthy and disease-free, which consistently results in high yields. To naturally deter pests, we recruit beneficial predatory insects like ladybugs and parasitic wasps, in addition to botanical oils and diatomaceous earth.
Precision Agriculture (PA) and Site-Specific Crop Management (SSCM) – We utilize technology to manage crops and increase farm efficiency, such as machine learning for fertilizer optimization and digital sensors in the field to monitor crops.
Soil Health and Terroir – Like grapes for wine, cannabis plants grown in the soil have terroir that affects the flower’s qualities, characteristics, terpene profile, aroma and taste, based on temperature, climate, soil composition and topography, as well as other environmental influences. Micro-climates matter – the same strain of cannabis grown along the coast likely has a different taste and potency than one grown inland. We grow in Santa Barbara wine country for the combination of fertile soil, hot sun, and cool nights which yield an incredibly diverse, potent and flavorful crop of cannabis flowers. Between growing seasons, we employ regenerative agriculture by planting cover crops including oat, beans, peas and buckwheat to add nitrogen and organic matter naturally back in the soil. This method of cover crops also helps reduce pests and soil-borne diseases in preparation for the next growing season. We know that an ideal environment in combination with healthy soil and good land management results in healthier, more vigorous plants, which translates to higher-quality products.
As farmers, it is our responsibility to care of the land with good management decisions today so that we grow the best quality products while better preserving the land for the future. It takes careful planning, knowledge of the land, a commitment to sustainable practices and a desire to put farming first.
In this “Flower-Side Chats” series of articles, Green interviews integrated cannabis companies and flower brands that are bringing unique business models to the industry. Particular attention is focused on how these businesses integrate innovative practices in order to navigate a rapidly changing landscape of regulatory, supply chain and consumer demand.
Large-scale agricultural practices can take a toll on soil health leading to inefficiencies over the long term. Harvey’s All Naturals is a Colorado-based company specializing in premium farm-to-table full spectrum CBD products. Harvey’s gets all of its hemp from Boot Ranch Farms, an off-grid sustainable hemp farm in Southern Colorado supplied by an artesian well.
We spoke with Harvey Craig, CEO Harvey’s All Naturals and co-founder of Boot Ranch Farms, to learn more about the benefits of regenerative agriculture, how he thinks about soil health, and how they produce their CBD products. Harvey started Boot Ranch Farms in 2014 after the passing of the Farm Bill and Harvey’s All Naturals followed shortly thereafter.
Aaron Green: How did you get involved in the cannabis and hemp industry?
Harvey Craig: I got involved at a very young age, as the youngest of eight kids, seven of which are boys, I was introduced to cannabis on the marijuana side first. As an engineer through the years, I’ve always been involved in creating very efficient growing systems for cannabis.
In the early 2000s, I learned about CBD a little bit through experimenting with marijuana strains to help a friend who had Parkinson’s and also through the research performed by Raphael Mechoulem, an organic chemist and professor at the Hebrew University of Jerusalem in Israel. In 2014, when the Farm Bill made hemp legal, I dropped everything and went into it because I felt “this is what I need to be doing.”
Green: What is sustainable farming mean to you?
Craig: Sustainable farming to me means putting soil health and responsible natural growing practices at the forefront of all agriculture – regenerative processes for soil, in a nutshell. To me, soil health is one of the biggest problems in the United States right now. By regenerating and making our soils living, healthy and with a rich nutrient base we create an ecosystem that is good for human health and health all around.
Green: What do you mean specifically when you say, “soil health?”
Craig: Soil is living. A good natural soil has a living microbiotic structure inside it. There’s a living habitat that forms inside our soil over the years. Large scale agriculture in many cases has depleted or killed this living structure through readily accessible fertilizers and tilling practices.
Farmers understand the soil. There are practices we can undertake that are helping our living soils and helping the microbiotic habitat to thrive. Practices such as no-till technologies, rotating crops, using cover crops, not being a monocrop, responsible water use, healthy fertilizer and pesticide technologies, minimal processing, the list goes on and on…
When we talk about this thing called sustainability, I think it’s very important that we understand there are two sides of cannabis. There’s the marijuana and then there’s the hemp. We can’t put those two together – they’re governed very differently. Hemp became legal through the Farm Bill and is governed by the Department of Agriculture. Hemp is just like any other crop out there really. That means we can mix hemp in with other crops. It’s very much like corn and other crops in how it’s grown on a large scale, industrial basis.
Marijuana on the other hand is governed by each state’s regulatory commission. Those regulations make it very hard to mix in with general agriculture. So, when it comes to the marijuana side, unfortunately, it must be a monocrop. Most marijuana is grown in pots and pots are fine. However, if you are just growing in a pot and then throwing your soil away, that is not very sustainable. As it sits right now, in the marijuana industry there is really no sustainability, unfortunately. The energy use for the lights in indoor grows, for example, creates a huge carbon footprint and load on the electrical grid. I’m not trying to put indoor growing down, but that’s the way it is. The only way I foresee sustainability in the marijuana side of cannabis is to let loose a little bit on regulation and allow it to become a part of normal agricultural processes.
Green: What is it about tilling that degrades the soil quality?
Craig: When we till our soil, we’re turning the organisms in the soil up and we’re allowing the sun to dry them out. If it’s not done properly, you kill that soil structure.
Now, these little microorganisms in our soil create a healthy soil, but it doesn’t happen instantly, this takes years to create. Nobody has the time anymore, everybody’s “go go go” and “make it happen instantly”. So that gets destroyed. Now we have all these dead soils that everybody’s growing in and growers turn to factory-produced fertilizers with readily available nutrients.
When we are talking about cannabis, we can’t just look at monocropping. If you grow one crop in the same soil over and over, the soil is going to get depleted. One of the main things that we deplete is nitrogen and growing other crops, such as clover, can replenish that nitrogen. Growing cover crops protects the soil from the sun, creates nitrogen for the soil, and holds the water within the soil.
Instead of tilling, you can rotate with crops like root vegetables, radishes and other things that have deep root structures. Instead of tearing them up, just let them degrade organically and go back into the soil. Those deep root structures will also help aerate the soil.
Green: What is a farmer’s first approach?
Craig: Farmers want their land to be healthy. True farmers have a oneness with the earth and understand the earth. The farmer’s first approach keeps the farmer involved in creating new technologies for agriculture.
Green: Let’s say you’re a farmer that has land or recently acquired land that’s been industrially grown upon. How would you take that land and start fresh with a regenerative process?
Craig: The first thing you have to do is take soil samples and send them to a lab. That’ll tell you what you’re working with. Also, knowing a little history about the land helps as well. Was it used for grazing? Was it used for growing corn? What was it used for? Were organic practices used?
Then, there are many things you can do to start to regenerate your soil, but it takes time. In many situations, people don’t want to take that time. But what we’re learning is, the people and the farmers that do take that time often take a hit monetarily for the first two or three years. After that, once that structure is maintained, the natural health of the soil can be replenished. Crops will grow better, and they won’t spend as much money on fertilizers and pesticides in the long run because the microbiotic structure in the soil is creating a healthy ecosystem. When we destroy that ecosystem, it doesn’t come back easily or quickly. If there’s a little bit there, it can be regenerated with the right practices.
Green: I understand that the Boot Ranch is an off-the-grid farm. What was your motivation for either going off-grid or remaining off-grid?
Craig: I have a background in alternative energies and engineering, and when creating Boot Ranch Farms there was a lot that went into the sustainability side of it. The farm is extremely far away from the power grid for starters. So, an investment in solar for electricity was money well spent. My thought process was, why would I invest in bringing the wires in when I could actually save money and resources by creating a very efficient solar system and not be tied to the grid? Our farm is self-sustaining without being connected to any grid, which is one of the main reasons for remaining off-grid.
Green: I understand the farm is supplied by an artesian well. How do you monitor your water quality?
Craig: Well, we’re very fortunate. Existing natural water quality is one of the main reasons we decided to grow in the San Luis Valley. When you’re starting something new, you have to look at your financial side of things. Investing in a hemp farm is very different than the marijuana side because you won’t make as much money per pound of product sold. So, you have to watch your budget and not spend too much, or you’re never going to make a profit.
The self-sustaining artisanal well and water rights were existing on the property. There’s no pumping required for it and the water goes into a 10,000-gallon holding tank, where we can monitor and test for water quality. In order to water our plants, we use a pump/drip water system that supplies water to each individual plant. It’s very efficient compared to most watering systems out there, such as flood irrigation or pivots, and really doesn’t use a heck of a lot of water.
Green: Are you growing in open air or greenhouses?
Craig: We grow in two 3,000 square feet industrial-grade greenhouses at Boot Ranch Farms. Greenhouse One has all the bells and whistles including heating, cooling, light deprivation, supplemental lighting, automated controls and more. That greenhouse allows us to mimic Mother Nature a little bit. We can get up to six harvests throughout the course of the year in that greenhouse. However, in reality, we get about four.
In addition, we have a second greenhouse that is set about 100 feet away and set up to keep plants growing on mother nature’s cycle. We can move groups of mature plants to Greenhouse One after each harvest for multiple flowering cycles. Lastly, between greenhouses, we have a 10,000 square foot courtyard that’s protected with shade cloth and other things to help protect those plants from the elements. In late October, all remaining plants in both greenhouses and the courtyard become mature and ready to harvest due to shorter days created by mother nature.
Green: Do you insure your crops?
Craig: We have not. Hemp is a new industry and we have not found good crop insurance.
Green: Do you cultivate your own genetics?
Craig: We work with some other companies here in Colorado to provide genetics. Consistent genetics are extremely important on the hemp side because we need to trust that they are going to keep the THC levels down. On the marijuana side, that part doesn’t matter so much
There are different strains that have been created that I absolutely love, and I’ve tried to stick with them and stay with that seed stock. One of them is called The Wife and the other Cherry Wine. Most of the best hemp I have found is based upon the Cherry strain. People are always looking for high CBD. I’d rather have a lower CBD level in the 8% to 12% range. Something higher in the 14% to 20% range has a higher chance of producing a product with more than the legal amount of THC.
Green: Is Harvey’s All Naturals fully supplied by Boot Ranch Farms?
Craig: Yes, it is. There are a lot of things that go into a quality product and we focus on that at Boot Ranch. We’re small, not trying to compete with the large-scale market. Unfortunately, a high percentage of the products out on the market come from large-scale industrial hemp grows. We focus on long-term medicinal value and grow very high-quality hemp and we try not to degrade it in any way, shape or form throughout processing.
Green: How many square feet or acres is the Boot Ranch Farm?
Craig: Boot Ranch farm is about 260 acres. We only grow on less than three of it.
Green: What’s your extraction process?
Craig: We use cold alcohol extraction. We do not distill to separate our alcohol from the hemp oil. We use what’s called a roto vape. That cold processing preserves our terpenes, it preserves our full-spectrum cannabis oil profile and doesn’t fully decarboxylate our CBDa. We want a large CBDa percentage because there are many things that CBDa is good for when it comes to long term medicinal reasons.
Green: Are you processing your own hemp?
Craig: No, we sub that part of it out. What I’ve learned in this industry is three main parts: 1- the farming; 2- the extraction, and; 3- the product line. Those are three very separate processes and require specialized expertise within themselves. Each is a large investment and it’s very hard to do it all. I decided to work with other people on the extraction part of it. They have the expertise, and we pay them well to do what they do.
Green: Okay, great. And then any final words for Ag Day?
Craig: Support your small farmer in nutrient-rich agricultural products.
Green: Great. That concludes the interview, Harvey!
In this article you will learn how to control pests and improve the health of your cannabis plants using integrated pest management, commonly referred to as IPM. This involves a multi-point strategy – there is no quick fix, nor is there one solution that will wipe out all your pest problems. Proper pest management requires patience, consistency and determination.
It is important to understand that not all pesticides are bad. While many are incredibly harmful not only to pests, but also humans, in this article I will educate you about some of the safer alternatives to traditional pesticides. It is possible to safely control unwanted pests in your cannabis garden without harming yourself, your employees or the natural habitat around you.
Every cultivation facility should have a well-thought-out plan for their pest management program. This program should account for the prevention, and if necessary, eradication of: spider mites, russet mites, fungus gnats, root aphids, thrips and caterpillars. These are just a few of the more common pests you’ll find in a cannabis garden. There could also be many other less commonly known bugs, so you have to be vigilant in looking closely at your plants, and the soil, at all times. Complete eradication of a targeted pest can be difficult. Once a pest has established itself, decimating or decreasing the population will require an aggressive regimen that includes spraying daily to control populations and prevent other pests from getting established.
Spraying or applying pesticides to the foliage of plants isn’t the only way to control or eradicate pest populations. There are many other ways that you can minimize the spread of pests without the use of pesticides. In greenhouse and outdoor grows, growing specific types of plants around the cultivation area will attract both beneficial and predator bugs that will naturally control pest populations. Some plants that attract these bugs are: mint, peppers, and marigold. Beneficial and predator bugs, such as ladybugs, predator wasps and predator mites, can control unwanted pest populations in the area before they even have a chance to become a problem in your garden. Plants and flowers that attract bees, birds and insects will also create helpful bio- diversity, making it more difficult for the unwanted pests to thrive.
For indoor cultivation, it is imperative that you have your cultivation facility set up for a proper workflow. If you already have pests, you need to make sure you are not contaminating the rest of your facility when going from one area to the next. Make sure that you only go to contaminated areas at the very end of your day, and when you’re done working in that area, you must immediately exit the building. Do not ever walk back through the uncontaminated parts of your facility or the pests will spread quickly.
When most people think of pests in their cannabis garden they think of the more common varieties: spider mites, russet mites, aphids and thrips. However, there are also soil-dwelling pests that can exist, without your knowledge. These will decrease the health and vigor of your plants, without you even knowing they’re there, if you’re not careful to check for them. Some of the soil dwelling pests that plague cannabis plants are: root aphids, fungus gnat larvae and grubs. It is just as important to control the pests below the soil, feeding on your roots, as it is to control the pests that feed above soil on your plants.
Maintaining healthy plants is essential to controlling pest populations, both on the foliage and below the soil. Healthy plants will have an easier time fighting off pests than unhealthy plants. Plants have immune systems just like humans, and the stronger the plant’s immune system, the more likely it will be able to ward off pests and diseases. Allowing a plant to reach its full potential, by minimizing pests, means your plants will also have a better quality, smell and flavor, not to mention a bigger yield.
Worker Safety, Regulation and REI times
The application of pesticides requires certification from the state agricultural department. In certain situations, depending on the type of pesticide and method of application, a license may even be required. The application of pesticides without proper certification is against the law. Applying pesticides in a manner that is not in accordance with the label and instructions is also a violation of law.
The proper personal protective equipment (PPE) is required for anybody handling, mixing or applying pesticides. Employees can be a liability to your company if they are applying pesticides improperly. Make sure you and your entire staff are well educated about pesticide use requirements and limitations, prior to usage, and that only a properly certified person is handling the mixing and application at your facility.
After a pesticide is applied, you must abide by the re-entry interval (REI). This is the required time period limiting all workers from re-entry into areas where pesticides have been applied. This time period will vary depending on the type of pesticide used and the method of application. In some instances, pesticides applied in the last 30 days may require employee training before work can be done in those areas.
The misuse of or improper handling of pesticides is not only unlawful and dangerous to human health, but can also cause environmental damage to waterways and wildlife. The direct effects of pesticides on wildlife include acute poisoning, immunotoxicity, endocrine disruption, reproductive failure, altered morphology and growth rates and changes in behavior. Pesticides can indirectly impact wildlife through reduction of food resources and refuses, starvation due to decreased prey availability, hypothermia and secondary poisoning. Section 1602 of the California Fish and Game Code governs requirements for permitting of any project where pesticides will be used, and strictly regulates the disposal of all waste and run-off. It is imperative to know the regulations and to abide by them, or heavy fines will ensue!
Using Pesticides in a Regulated Market
Knowing which pesticides you can’t use, to avoid failing mandatory state testing, is just as important as knowing which ones you can use safely to pass required testing. Most states with regulated markets have strict limitations on the pesticides that can be used in cannabis cultivation. Pesticide use in the cultivation of cannabis is the most strictly regulated in the agriculture industry; the pesticides allowed for use in cannabis cultivation are far more limited than any other crop.
Just because a product is certified organic does not mean that it can be used, or that it is safe to be consumed or ingested. Oftentimes when cannabis flower alone is tested it will not fail or show a detectable amount of pesticides or heavy metals. However, when that flower is turned into concentrates, banned substances are then detected in testing, leading to test failures.
Cannabis cultivation facilities that are located on land that was previously used for conventional agriculture, or located near vineyards or other agricultural crops that are heavily sprayed with harmful pesticides, run a very high-risk failing testing. This is because of either spray drift from nearby agriculture, or residual pesticides and heavy metals left in the soil from previous crops that were using pesticides banned for cannabis cultivation. Accordingly, if you’re going to be growing outdoors or in a greenhouse, it is imperative that you get a soil and water test prior to cultivation, so you can determine if there is any potential for test failures due to pesticides or heavy metals in the soil or water in that area.
Proper Application – Using the Right Tools in the Right Way at the Right Time
One of the most important factors in pest management is proper identification of pests and proper application and coverage of pesticides. It does not require an entomology degree to identify insects, these days there is a lot of information online that can help you identify cannabis pests. Proper identification of insects can make the difference between success and failure. With a good eye and a microscope, if you do your research, you can control most insects in your garden.
In order to control pests in your garden you must get proper coverage of the foliage of the plant when you are applying pesticides. There are different types of equipment that are commonly used to apply pesticides in cannabis cultivation: backpack sprayers, foggers, and airless paint sprayers are the most common. An alternative method involves using an automated dosing system such as a dosatron, which injects fertilizer or pesticides at a specific ratio into your water lines, allowing you to use only the exact amount of pesticide you need. That way you avoid wasting money on unused pesticides. It is also safer for employees because it minimizes employee exposure, since there is no mixing required, and it allows for a large volume to be sprayed, without refilling a tank or a backpack sprayer.
No matter what you are using you must ensure you get the proper coverage on your plants in order to control pests. The temperature and humidity of your cultivation area, as well as the PH and temperature of the pesticide solution, all factor into the success of your IPM. For example, PFR 97 needs to be applied at a higher humidity range, around 70% to be most effective. In some areas this is not possible so repeated applications may be required to ensure the application is effective. A high PH or alkaline PH can cause alkaline hydrolysis which will make your pesticide solution less effective and will dictate how long your pesticides remain effective after they are mixed. It is therefore important to use your pesticide solution as soon as you make it; don’t let it sit around for long periods of time before use or it will be less effective.
In cannabis cultivation there are two different primary growth cycles: vegetative and flower. These cycles require different IPM strategies. In general, during the flowering cycle, pesticides should not be applied after the second week, with some limited exceptions i.e. for outdoor cultivation there is a longer window to spray since the flower set takes longer than a plant being grown inside, or in a light deprivation greenhouse, where there is a 12/12 flowering cycle.
For the vegetative (non-flowering) cycle, a strict rotation of foliage spray applications targeting not only pests, but also molds and pathogens, will be necessary to avoid a quick onset of infestation. Starting with an immaculate vegetation room is crucial to maintaining pest and mold free plants in the flowering cycle. Preventative sprays that are safe for use include: safer soap (contact kill) for soft bodied chewing insects; Regalia (biological control) for powdery mildew; and PFR 97 (biological control) for soft bodied chewing insects. It is also helpful to spray kelp, which strengthens the cell walls of plants, making the plant healthier, and thus enabling the plant to better defend itself from pests and diseases. Also, Bacillus thuringiensis (Bt) is useful to prevent or kill caterpillars.
The best way to control a pest infestation in the flowering cycle is at the very beginning on day one. You must start aggressively, with a three-way control consisting of a contact kill and preventative during days 1-14; preventative and biological control during days 10-18; and then release predator bugs on day 25, for optimal results. Knocking back the population with an effective contact kill pesticide early on is essential to ultimately lowering populations throughout the grow cycle, so that you can spray a biological control to preclude them from returning, before you release the predatory bugs at the end of the cycle.
Biological controls can take anywhere from 3 to 10 days before they are effective. Biological pesticides are selected strains of bacteria or fungus. When the plant tissue is eaten by a targeted pest, the bacteria kills the pest from the inside providing control without having to spray pesticides repeatedly. Predator bugs are the last line of defense, used in late flowering. They can be used indoors, outdoors and in greenhouses. An example of a common predator bug is Amblyseius californicus used to control low populations of spider mites, but there are many different varieties and they are specific depending on the type of pest population you seek to control.
A common concern with the use of predatory bugs, is whether they will be present when the flowers are harvested. However, if there is no food for the bugs (i.e. pests) the predator bugs will leave in search of food elsewhere. Further, indoor predator bugs are usually very small in size and difficult to see to an untrained eye. It is very unlikely to see any signs of predator bugs near the end of the flowering cycle, or in the finished flower product. Even when using bigger predator bugs, the bugs will leave the plants when harvested and dried.
Having pests can be very stressful. It is not uncommon to have bugs, pests, rodents, animals and birds cause damage in cannabis gardens. Making an informed decision based on science and not on unproven assumptions can determine how successful you are at pest management. There are many factors that go into pest management and no one situation is the same. You must be dedicated and consistent; pest management never stops. You will always have something ready to invade your garden. Prepare, plan, prevent and repeat!
Before you begin any large-scale cultivation project, you must necessarily consider the four factors highlighted below, among many others, to ensure your cultivation is successful. Failure to do so will cost you greatly in both time and money, and ultimately could lead to failure. While the four areas highlighted below may be the most important considerations to address, you should hire a cultivation advisor to determine the numerous other considerations you must deal with before you begin.
Genetics will play a huge role in your cultivation plan, as they can ultimately make or break the success of your business. Access to quality, verified genetics will greatly affect your profits. All cannabis genetics grow differently and may require different conditions and nutrients. Further, consumers in today’s regulated market have greater awareness; they are much more knowledgeable about genetics and able to discern between quality cannabis versus commercially produced cannabis.
Market trends will dictate whether or not you’ll ultimately be able to sell your harvest at market rate. You need to project out at least one year in advance the genetics you will be growing. But often it is impossible to predict what consumers will be purchasing a year in advance so this part of your cultivation plan should be well thought out. Further compounding this difficulty is the fact that it may take six months to ramp up production of any given variety.
Genetics that are popular now may still be popular next year, but that also means there will be more competition for shelf space, as more competitors will also likely be growing these same genetics. Therefore, don’t rely on only one trendy variety as the bulk of your selection for the year, no matter how popular it is at the moment. Producing a single variety as the bulk of your crop is always risky, unless you have a contract with a sales outlet, in advance, for a set quantity of that one particular variety. Diversity in your genetics is beneficial, when chosen correctly.
Making proprietary genetics from your own seed collection can give you a big advantage in today’s competitive market. Having a variety with a distinct, unique and desirable smell, taste, effect or cannabinoid profile will allow you to distinguish your brand amongst others. Entire brands have been built off of a single variety: Cookies and Lemontree are two examples of companies that have done this. All it takes is one really good variety to attract a lot of attention to your brand. Having your own breeding project on site will allow you to look for and identify varieties that work for you and your business model, and ultimately will help to distinguish your brand apart from others.
Only buy seeds from reputable breeders! Any new varieties that you are going to be cultivating should be tested out at least three times, on a small scale, before being moved into a full production model. If you are growing from seed there is always the potential for your crop to get pollinated by male plants or hermaphrodites that went unnoticed, and therefore, they could be a potential risk to your entire harvest. Treat them accordingly, i.e. by cultivating them on a small scale in a separate, enclosed area.
Buying clones from a commercial nursery can be risky. Genetics are passed from one grower to another haphazardly, and names are changed far too easily. This can create a lot of confusion as to what variety you are actually purchasing and whether you are getting the best version of the genetics. Just because a clone is called “sour diesel” doesn’t mean you’re actually getting the real, authentic sour diesel. And to further complicate things, the same clone grown in different environments can produce a noticeable difference in flavor, smell and effect depending on your cultivation method. Always try your best to verify the authenticity of the genetics you purchase. Ask about the history and origin of the particular genetics you are purchasing. Better yet, ask for pictures, physical samples, and most importantly, certificates of analysis from a laboratory, indicating the potency. In many states anything under 20% THC is going to be hard to sell, while anything over 30% will easily sell and command the highest price. It’s a good idea to have a laboratory test the terpene profile in order to verify a variety is actually what the seller purports it to be.
Knowing the source of your genetics is imperative. It will help ensure that you actually have the variety that you were intending to grow, and therefore, allow you to achieve your intended results. Knowing what varieties you are going to cultivate, before you grow them, will also give you a better idea of the ideal growing conditions for that specific variety, as well as what nutrients will be required to achieve optimum output.
2. Automated Watering Systems
Installing an automated watering system, during build out, will by far be the most cost-effective use of your money, and will save you the most amount of time in labor. An automated watering system, commonly referred to as a “drip system” or “drip irrigation,” is necessary regardless of whether you are cultivating indoors or outdoors; it will allow you to water multiple different areas at once, or only water a few specific areas of the garden at one time. Hand watering a 22,000 square-foot cultivation site will take one person eight hours every single day, on average, to maintain. However, a properly designed drip system can water an entire large-scale garden in a couple of hours, without any employees, record all the relevant data and notify you if there is a problem. This enables you more time to spend closely inspecting the plants to ensure there are no bugs or other problems present, and that your plants are healthy and thriving. This attention to detail is necessary if you want to have consistent success.
Automated watering systems not only save a great deal of time but also eliminate the possibility of human error, like over watering, which can kill an entire crop quickly. There aresoil moisture sensors that can be placed in the soil to regulate the supply of water to the plants in a precise manner. Without an extremely skilled, experienced work force, damage to plants due to over watering is very common. A drip system will reduce the threat of human error by ensuring delivery of precisely the correct amount of water and nutrients to each plant every single time they are watered.
Not all drip systems are created equally. There are different types of automated watering systems. Designing the right drip system for your cultivation site(s) can be complicated. Make sure you do your research, or better yet, work with a cultivation advisor who has experience with automated irrigation systems in conjunction with a licensed plumber, to ensure you are installing the best system for your particular set up.
Adding a fertilizer injector to your drip system can further increase the efficiency of your operation and save you money on nutrients by using only what you need and ensuring correct application. Again, automating this process will save you time and money, and reduce the threat of human error.
The types of nutrients you use and the amount of nutrients you use, are going to directly affect the quality of your cannabis flower. Conventional agriculture and Dutch hydroponic cannabis cultivation have always used salt-based fertilizers. However, they can be toxic for the plant in high amounts. While cheap and easy to use, salt- based nutrients are made in big factories using chemical processes to manufacture. They are not good for the environment, and overall, they produce an inferior product. The highest quality cannabis, is grown with organic living soil. Although seemingly contrary to popular knowledge, when done properly, cultivating in organic living soil is more cost effective than using powdered or liquid salt-based fertilizers.
Yield and quality depend on the skills of the cultivator, more than the method they are using. Having healthy plants from the start, will always yield better results, no matter what way they were grown. In my 20 years of experience I have seen plants grown in balanced living soil yield just as much as plants grown with synthetic nutrients. Further, the quality is not comparable.
Always remember, it is the quality of your flower that will determine the price it is sold for, not the yield. Even if you produce more overall weight of chemically grown cannabis, if nobody wants to purchase that product, then you are going to yield far less profit than another company growing in the same amount of space using organic practices that yield a higher quality product.
The difference in quality between plants grown in balanced living soil versus any other method of cultivation is undeniable. It is really easy to post a pretty picture of a flower on Instagram but that picture doesn’t tell you anything about what went into producing it. When flower is produced using chemical nutrients, it is likely going to be harsh and not enjoyable to smoke. Lesson learned: don’t judge a bud by an Instagram photo! There is a stark difference between cannabis grown using synthetic nutrients versus cannabis grown in living soil. Once you’ve experienced the difference you will never want to consume cannabis that is grown any other way.
4. Plant Propagation
Having the ability to propagate your own clones, from mother plants that you have cultivated, can save you a staggering amount of money. In some states, having a cultivation license allows you to produce your own clones for your cultivation, while having a nursery permit will allow you to sell clones for commercial sales to other companies. The average price of a wholesale clone is around eight dollars. If you require 5000 plants for every harvest, that’s a $40,000 expense you must bear, every grow cycle. This can obviously add up quickly. And as previously mentioned there’s the risk of purchasing inferior genetics or unhealthy plants, both of which greatly affect your profit margins.
On the other hand, the cost of materials and labor to produce a healthy clone can be as low as one dollar when using advanced cloning techniques. Controlling your clone supply can ensure they are healthy and allow you to know exactly what you are growing each time. Further, it doesn’t take a lot of space to propagate your own cuttings. In a 400 square-foot space one could produce between 5,000 to 10,000 clones per month, all of which could be maintained by one person depending on your situation.
And last but definitely not least, the most important thing you can do to ensure the success of your cultivation, is hire an experienced knowledgeable grower who is passionate about cannabis. The success of your company depends on it. You need someone with the knowledge, experience, and skills to make your cultivation dreams a reality. You need someone who can plan your build-out and cultivation to ensure success from the start. And you need someone with the skills to handle the multitude of inevitable problems that will arise in a cost effective and efficient way.
These are just some of the many considerations you must account for when planning a large scale grow in the regulated market. An experienced cultivation advisor can help you with these, and many other considerations you will need to contend with before you begin your grow. Creating a well thought out plan at the outset can end up saving you thousands, if not hundreds of thousands of dollars down the road.
Editor’s Note: The following is based on research and studies performed in their Santa Cruz Lab, with contributions from Mikhail Gadomski, Lab Manager, Ryan Maus Technical Services Analyst, Laurie Post, Director of Food Safety & Compliance, and Charles Deibel, President Deibel Cannabis Labs.
Heavy metals are common environmental contaminants resulting from human industrial activities such as mining operations, industrial waste, automotive emissions, coal fired power plants and farm/house hold water run-off. They affect the water and soil, and become concentrated in plants, animals, pesticides and the sediments used to make fertilizers. They can also be present in low quality glass or plastic packaging materials that can leach into the final cannabis product upon contact. The inputs used by cultivators that can be contaminated with heavy metals include fertilizers, growing media, air, water and even the clone/plant itself.
The four heavy metals tested in the cannabis industry are lead, arsenic, mercury and cadmium. The California Bureau of Cannabis Control (BCC) mandates heavy metals testing for all three categories of cannabis products (inhalable cannabis, inhalable cannabis products and other cannabis and cannabis products) starting December 31, 2018. On an ongoing basis, we recommend cultivators test for the regulated heavy metals in R&D samples any time there are changes in a growing process including changes to growing media, cannabis strains, a water system or source, packaging materials and fertilizers or pesticides. Cultivators should test the soil, nutrient medium, water and any new clones or plants for heavy metals. Pre-qualifying a new packaging material supplier or a water source prior to use is a proactive approach that could bypass issues with finished product.
The best approach to heavy metal detection is the use of an instrument called an Inductively Coupled Plasma Mass Spectrometry (ICP-MS). There are many other instruments that can test for heavy metals, but in order to achieve the very low detection limits imposed by most states including California, the detector must be the ICP-MS. Prior to detection using ICP-MS, cannabis and cannabis related products go through a sample preparation stage consisting of some form of digestion to completely break down the complex matrix and extract the heavy metals for analysis. This two-step process is relatively fast and can be done in a single day, however, the instruments used to perform the digestion are usually the limiting step as the digesters run in a batch of 8-16 samples over a 2-hour period.
Only trace amounts of heavy metals are allowed by California’s BCC in cannabis and cannabis products. A highly sensitive detection system finds these trace amounts and also allows troubleshooting when a product is found to be out of specification.
For example, during the course of testing, we have seen lead levels exceed the BCC’s allowable limit of 0.5 ppm in resin from plastic vape cartridges. An investigation determined that the plastic used to make the vape cartridge was the source of the excessive lead levels. Even if a concentrate passes the limits at the time of sampling, the concern is that over time, the lead leached from the plastic into the resin, increasing the concentration of heavy metals to unsafe levels.
Getting a Representative Sample
The ability to detect trace levels of heavy metals is based on the sample size and how well the sample represents the entire batch. The current California recommended amount of sample is 1 gram of product per batch. Batch sizes can vary but cannot be larger than 50 pounds of flower. There is no upper limit to the batch sizes for other inhalable cannabis products (Category II).
It is entirely likely that two different 1 gram samples of flower can have two different results for heavy metals because of how small a sample is collected compared to an entire batch. In addition, has the entire plant evenly collected and concentrated the heavy metals into every square inch of it’s leaves? No, probably not. In fact, preliminary research in leafy greens shows that heavy metals are not evenly distributed in a plant. Results from soil testing can also be inconsistent due to clumping or granularity. Heavy metals are not equally distributed within a lot of soil and the one small sample that is taken may not represent the entire batch. That is why it is imperative to take a “random” sample by collecting several smaller samples from different areas of the entire batch, combining them, and taking a 1 g sample from this composite for analysis.
Linger, P. J. Mussig, H. Fischer, J. Kobert. 2002. Industrial hemp (Cannabis sativa L.) growing on heavy metal contaminated soil: fibre quality and phytoremediation potential. Ind. Crops Prod. 11, 73–84.
No matter the size of your cannabis greenhouse operation, keeping your plants alive and healthy requires the best possible growing environment. This means greenhouse managers and personnel must frequently monitor the status of environmental conditions and equipment. The sooner someone discovers extreme temperature fluctuations, rising humidity or equipment failure, the more inventory you can save.
That’s why integrating a remote monitoring system into your greenhouse operation can save you time, money and anxiety. Monitoring systems that use cloud-based technology let you see real-time status of all monitored conditions and receive alerts right on your mobile device.
Installing a monitoring system and sensors can be easier than you might think. Here are answers to ten questions to ask before installing a cloud-based monitoring system:
What is required to use a remote monitoring system?
Most remote monitoring systems require an internet or WiFi connection and access to an electrical outlet. Programming is done through a website, so it’s easiest to use a computer for the initial setup. If you don’t have an internet connection at your location, you’ll want to choose a cellular system. Make sure that there’s sufficient signal strength at your site, and check the signal quality in the area before purchasing a cellular device.
2. How do we determine what kind of monitoring system and sensors we need?
A reputable manufacturer will have a well-trained support team that can assess your needs even without a site visit to determine which products are best for your application. If you feel you need them to check out your greenhouse operation,many companies can set up a video conference or FaceTime chat to substitute for being on site.
You will want to provide details about the scope and purpose of your cannabis growing operation. Important factors to discuss include:
Skeletal structure of the greenhouse (metal, plastic, wood, etc.) and the covering material (glass or plastic).
Floor space square footage and height of each of your greenhouses.
Number of greenhouse structures in your operation.
Outdoor climate to determine if you rely more on heating or air conditioning and the level of humidity control needed.
Space dedicated to phases of growth (cloning and propagation, vegetative, flowering) and the microclimates needed for each.
Types of lighting, ventilation and irrigation systems.
Level of technological automation versus manual operation in place.
The monitoring system representative will then determine the type of system that would best serve your operation, the number of base units you will need and the types of sensors required.
The representative should also be able to provide tips on the placement of the sensors you’re purchasing. For example, to ensure thorough air temperature coverage, place sensors throughout the greenhouse, next to the thermostat controlling the room temperature and in the center of the greenhouse out of direct sunlight.
Note that there shouldn’t be a cost for a demo, consultation or assistance throughout the sales process. Be sure to ask if there are any fees or licenses to keep using the monitoring equipment after you purchase it.
3. Are sensors included with the monitoring system?
In most cases, sensors are sold separately. The sensors you select depend upon the conditions you want to monitor and how many you can connect to your base unit. Certainly, temperature is critical, but there are many other factors to deal with as well, such as humidity, CO2, soil moisture, water pH, power and equipment failure, ventilation and physical security.
For example, humidity has a direct impact on the photosynthesis and transpiration of plants. High humidity can also cause disease and promote the growth of harmful mold, algae and mildew. Sensors can detect changes in humidity levels.
Like any other plant, cannabis needs CO2 to thrive, so it’s a good idea to include a CO2 sensor that will signal to the monitoring device when readings go out of the preset range. There are even sensors that you can place in the soil to measure moisture content to help prevent over- or underwatering, budget water usage costs, promote growth and increase crop yield and quality.
Of course, all the critical systems in your growing facility—from water pumps to irrigation lines to louvers—rely on electrical power. A power outage monitoring sensor detects power failure. It can also monitor equipment for conditions that predict if a problem is looming, such as power fluctuations that occur at specific times.
Ventilation systems not only help control temperature, they also provide fresh air that is critical to plant health. Automated systems include features like vented roofs, side vents and forced fans. Sensors placed on all these systems will send personnel an alert if they stop running or operate outside of preset parameters.
To monitor the physical security of your greenhouses, you can add sensors to entrance doors, windows, supply rooms and equipment sheds. During off hours, when no staff is on duty, you can remain vigilant and be alerted to any unauthorized entry into your facility.
4. Do monitoring systems only work with the manufacturer’s sensors?
Not necessarily. For example, certain monitoring units can connect with most 4-20mA sensors and transmitters regardless of the brand. When selecting sensors, you might have a choice between ones that are designed by the manufacturer to work specifically with the monitoring system or universal components made by a third party. If the components aren’t made by the system manufacturer, you’ll want to find out if they have been tested with the monitor you are choosing and if you need to work with another vendor to purchase the parts.
5. Is a monitoring system easy to set up, or do we need to hire an electrician?
Many monitoring systems are quick and easy to install, and users can often set them up without hiring an outside expert. Look for one that requires only a few simple physical installation steps. For example:
Mount the device to the wall or somewhere secure;
Plug it into an electrical outlet and an internet connection;
Connect the sensors.
You connect the sensors to the base unit’s terminal strip using wire, which is included with many sensors. The range of many wired sensors can be extended up to 2,000 feet away from the base unit by adding wire that can be easily purchased at any home store. It’s a good idea to hire an electrician if you need to run wires through walls or ceilings.
Usually, once you plug in the device and connect the sensors, you then create an account on the manufacturer’s designated website and begin using your device. There should be no fee to create an account and use the site.
If the manufacturer doesn’t offer installation services, ask if they can recommend a local representative in your area who can set up your system. If not, make sure they provide free technical support via phone or email to walk you through the installation and answer any questions you might have about programming and daily usage.
6. Is there a monthly fee to access all the functionality of a monitoring device?
Many web- or cloud-based systems provide free functionality with some limitations. You might have to purchase a premium subscription to unlock features such as text messaging, phone call alerts and unlimited data logging access.
7. Should we get a system that is wired or wireless? Will we need to have a phone line, cable, internet or something else?
Wireless can mean two different things as it relates to monitoring: how the system communicates its data to the outside world and how the sensors communicate with the system.
The most popular systems require an internet or WiFi connection, but if that’s not an option, cellular- and phone-based systems are available.
A hardwired monitoring system connects the sensors to the base device with wires. A wireless system uses built-in radio transmitters to communicate with the base unit. Some monitoring systems can accommodate a combination of hardwired and wireless sensors.
8. Can one system monitor several sensor inputs around the clock?
Once the monitoring system is installed and programmed, it will constantly read the information from the sensors 24/7. Cloud-based systems have data logging capabilities and store limitless amounts of information that you can view from any internet-connected device via a website or app.
If the system detects any sensor readings outside of the preset range, it will send an alarm to all designated personnel. The number of sensors a base unit can monitor varies. Make sure to evaluate your needs and to select one that can accommodate your present situation and future growth.
When a monitoring system identifies a change in status, it immediately sends alerts to people on your contact list. If you don’t want all your personnel to receive notifications at the same time, some devices can be programmed to send alerts in a tiered fashion or on a schedule. Multiple communications methods like phone, email and text provide extra assurance that you’ll get the alert. It’s a good idea to check the number of people the system can reach and if the system automatically cycles through the contact list until someone responds. Some systems allow for flexible scheduling, so that off-duty personnel don’t receive alerts.
9. Do monitoring systems have a back-up power system that will ensure the alarming function still works if the power goes out or if someone disconnects the power?
The safest choice is a cloud-based system that comes with a built-in battery backup that will last for hours in the event of a power failure. Cloud-based units constantly communicate a signal to the cloud to validate its online status. If the communication link is interrupted—for example by a power outage or an employee accidently switching off the unit—the system generates an alarm indicating that the internet connection is lost or that there is a cellular communications problem. Users are alerted about the disruption through phone, text or email. All data collected during this time will be stored in the device and will be uploaded to the cloud when the internet connection is restored.
If you opt for a cloud-based monitoring system, make sure the infrastructure used to create the cloud platform is monitored 24/7 by the manufacturer’s team. Ask if they have multiple backups across the country to ensure the system is never down.
10. What should we expect if we need technical support or repairs to the system?
Purchase your system from a reputable manufacturer that provides a warranty and offers full repair services in the event the product stops working as it should. Also, research to make sure their tech support team is knowledgeable and willing to walk you through any questions you have about your monitoring system. Often, support specialists can diagnose and correct unit setup and programming issues over the phone.
It helps to record your observations regarding the problem, so the tech team can look for trends and circumstances concerning the issue and better diagnose the problem. Ideally, the manufacturer can provide loaner units if your problem requires mailing the device to their facility for repair.
As the cannabis industry in the United States and throughout the world develops, the market is getting more competitive. Markets in a number of states are experiencing disruptions that will have lasting effects for cultivators, including oversupply and supply chain bottlenecks. Now more than ever, growers need to look for ways to differentiate their product or gain a bigger market share. Looking at yield efficiency, quality improvements and analyzing the cost of inputs versus value of the crop can help growers make the right choices in technology for lighting, irrigation and pest control among other technologies.
A series of free webinars in two weeks can help growers learn about some of the more advanced techniques in improving yield and quality. The Cannabis Cultivation Virtual Conference on May 23rd will explore a variety of tips and tricks for taking their cultivation operation to the next level. This event is free to attendees, made possible by sponsors VividGro and CannaGrow Expo.
Attendees will hear from experts in cannabis cultivation on a range of topics, including breeding, drying, curing, environmental monitoring and micropropagation. Adam Jacques, co-founder of Growers’ Guild Gardens and Sproutly, will discuss some of his experience with breeding high-CBD strains in Oregon. His talk will delve into some of the proper breeding procedures, along with how to hunt for particular phenotypes and developing specific cannabinoids and terpenes.
Dr. Allison Justice, vice president of cultivation at Outco, is going to present some of her findings in drying and curing at the company. She plans on sharing her research on how the post-harvest stages can affect and control the chemical makeup of flower. She’ll also discuss some new protocols to monitor the dry and cure of cannabis flowers so we are able to modulate the terpene and cannabinoid profiles.
The technology portfolio, aimed at larger, commercial-scale growers, is essentially a network of monitors, sensors and controls that give cultivators real-time data on things like temperature, humidity, light, barometric pressure and other key factors. The idea of using IoT and hypersensitive monitoring is not new to horticulture, food or agriculture, but this is certainly a very new development for the cannabis growing space.
According to Brad Nattrass, chief executive officer and co-founder of urban-gro, it’s technology like this that’ll help growers control microclimates, helping them make the minor adjustments needed to ultimately improve yield and quality. “As ROI and optimized yields become increasingly important for commercial cultivators, the need for technologies that deliver rich granular data and real-time insights becomes critical,” says Nattrass. “With the ability to comprehensively sense, monitor, and control the microclimates throughout your facility in real-time, cultivators will be able to make proactive decisions to maximize yields.”
One of the more exciting aspects of this platform is the integration of sensors, and controls with automation. With the system monitoring and controlling fertigation, lighting and climate, it can detect when conditions are not ideal, which gives a cultivator valuable insights for directing pest management or HVAC decisions, according to Dan Droller, vice president of corporate development with urban-gro. “As we add more data, for example, adding alerts for when temperatures falls or humidity spikes can tell a grower to be on the lookout for powdery mildew,” says Droller. “We saw a corner of a bench get hot in the system’s monitoring, based on predefined alerts, which told us a bench fan was broken.” Hooking up a lot of these nodes and sensors with IoT and their platform allows the grower to get real-time monitoring on the entire operation, from anywhere with an Internet connection.
Droller says using more and more sensors creates super high-density data, which translates to being able to see a problem quickly and regroup on the fly. “Cannabis growers need to maintain ideal conditions, usually they do that with a handful of sensors right now,” says Droller. “They get peace of mind based on two or three sensors sending data points back. Our technology scales to the plant and bench level, connecting all of the aggregate data in one automated system.”
In the future, urban-gro is anticipating this will lay the groundwork for using artificial intelligence to learn when controls need to be adjusted based on the monitoring. Droller hopes to see the data from environmental conditions mapped with yield and by strain type, which could allow for ultra-precise breeding based on environmental conditions. “As we add more and more data and develop the platform further, we can deliver some elements of AI in the future, with increased controls and more scientific data,” says Droller.
Controlling your grow environment doesn’t start when you germinate your first seeds, it starts before you build your grow. There are steps you can take that will have a significant impact on mold growth and contamination, and these will vary based on the grow environment you choose.
Below is a roadmap to where each grow environment stands in terms of mold and contamination risk, and simple steps you can take to mitigate these factors.
The benefits of an outdoor grow are significant – using natural sunlight to grow plants is both inexpensive and environmentally sound. However, it allows the least amount of control and makes plants susceptible to weather conditions and outdoor contaminants including dust, wind, rain and insects. Depending on humidity and precipitation levels, mold can be a big issue as well.
When selecting an outdoor area for a cannabis farm, there are two important factors to consider: location and neighboring farmland. Geographical environments and sub-climates vary and once you have purchased land, you are committed, so be sure to consider these factors prior to purchase.
While arid desert climates have abundant sunlight and long growing seasons, flat, dry lands are subject to dust-storms, flash floods and exceedingly high winds that can damage crops. Conversely, more protected areas often have high humidity and rainfall late in the season, which can create huge issues with bud rot and mold. Neighboring farms also have an impact on your grow, so be sure to find out what they cultivate, what they spray, their harvest schedule and how they run their operation. Large farming equipment kicks up a lot of contaminant-laden dust and can damage crops by displacing insects to your farm if they harvest before you. Pesticide drift is also a major issue as even tiny amounts from a neighbor’s farm can cause your crops to fail testing, depending on what state you are in.
With outdoor grow environments always at the mercy of Mother Nature, any cultivator is wise to control contamination potential on the ground. Cover soil and protect your crop by planting cover crops and laying plastic mulch on as much ground as reasonable. In many cases it makes sense to irrigate uncultivated parts of your farm just to keep dust down.
Greenhouses are the future of cannabis cultivation. They allow growers to capture the full spectrum and power of the sun while lessening environmental impact and operating expenses, while still being able to precisely control the environment to grow great cannabis. With recent advancements in greenhouse technology such as automated control systems, positive pressure, geothermal heating or cooling and LED supplemental lighting, greenhouses are the future. However, older or economy greenhouses that take in unfiltered air from outside still have a medium amount of mold and contamination risk.
Before building your greenhouse, study the area while taking into account climate, weather conditions and sun exposure. Excessively windy areas can blow in contaminants, and extremely hot climates make cooling the greenhouse interior a challenging and costly endeavor.
There are several simple operational tactics to reduce contaminants in a greenhouse. Add a thrip screen to keep insects out, thoroughly clean pad walls with an oxidizing agent after each cycle, and keep plants at least 10 feet from pad walls. Plan to flip the entire greenhouse at once so that you can clean the greenhouse top to bottom before your next crop. A continuous harvest in your greenhouse allows contaminants to jump from one plant to the next and reduces the ability to control your environment and eliminate problems at the end of a cycle. Lastly, open shade curtains slowly in the morning. This prevents temperature inversion and condensation, which can cause water drops to fall from the ceiling and transfer contaminants onto plants below.
An indoor environment offers ultimate control to any grow operation. Cultivators can grow high-quality cannabis with the smallest potential for yeast and mold growth. Unfortunately, indoor environments are extremely expensive, inefficient and environmentally costly.
With indoor grow environments, keeping mold and contaminants at bay comes down to following a regimented plan that keeps all grow aspects clean and in order. To keep your grow environment clean, change HVAC filters multiple times a month. It’s also important to install HEPA filters and UV lights in HVAC systems to further reduce contamination threats. Clearly mark air returns if they are near the ground and keep those areas free of clutter. They are the lungs of your grow. Also, stop using brooms in the grow space. They stir up a lot of contaminants that have settled to the floor. Instead, use HEPA filter backpack vacuums or install a central vacuum system. Set up a “dirty room” for anything messy on a separate HVAC system, and be sure to thoroughly clean pots after every harvest cycle.
Editor’s note: This article should serve as a foundation of knowledge for yeast and mold in cannabis. Beginning in January 2018, we will publish a series of articles focused entirely on yeast and mold, discussing topics such as TYMC testing, preventing yeast and mold in cultivation and treatment methods to reduce yeast and mold.
Cannabis stakeholders, including cultivators, extractors, brokers, distributors and consumers, have been active in the shadows for decades. With the legalization of recreational adult use in several states, and more on the way, safety of the distributed product is one of the main concerns for regulators and the public. Currently, Colorado1, Nevada and Canada2 require total yeast and mold count (TYMC) compliance testing to evaluate whether or not cannabis is safe for human consumption. As the cannabis industry matures, it is likely that TYMC or other stringent testing for yeast and mold will be adopted in the increasingly regulated medical and recreational markets.
The goal of this article is to provide general information on yeast and mold, and to explain why TYMC is an important indicator in determining cannabis safety.
Yeast & Mold
Yeast and mold are members of the fungi family. Fungus, widespread in nature, can be found in the air, water, soil, vegetation and in decaying matter. The types of fungus found in different geographic regions vary based upon humidity, soil and other environmental conditions. In general, fungi can grow in a wide range of pH environments and temperatures, and can survive in harsh conditions that bacteria cannot. They are not able to produce their own food like plants, and survive by breaking down material from their surroundings into nutrients. Mold cannot thrive in an environment with limited oxygen, while yeast is able to grow with or without oxygen. Most molds, if grown for a long enough period, can be detected visually, while yeast growth is usually detected by off-flavor and fermentation.
Due to their versatility, it is rare to find a place or surface that is naturally free of fungi or their spores. Damp conditions, poor air quality and darker areas are inviting environments for yeast and mold growth.
Cannabis plants are grown in both indoor and outdoor conditions. Plants grown outdoors are exposed to wider ranges and larger populations of fungal species compared to indoor plants. However, factors such as improper watering, the type of soil and fertilizer and poor air circulation can all increase the chance of mold growth in indoor environments. Moreover, secondary contamination is a prevalent risk from human handling during harvest and trimming for both indoor and outdoor-grown cannabis. If humidity and temperature levels of drying and curing rooms are not carefully controlled, the final product could also easily develop fungi or their growth by-product.
What is TYMC?
TYMC, or total yeast and mold count, is the number of colony forming units present per gram of product (CFU/g). A colony forming unit is the scientific means of counting and reporting the population of live bacteria or yeast and mold in a product. To determine the count, the cannabis sample is plated on a petri dish which is then incubated at a specific temperature for three to five days. During this time, the yeast and mold present will grow and reproduce. Each colony, which represents an individual or a group of yeast and mold, produces one spot on the petri dish. Each spot is considered one colony forming unit.
Why is TYMC Measured?
TYMC is an indicator of the overall cleanliness of the product’s life cycle: growing environment, processing conditions, material handling and storage facilities. Mold by itself is not considered “bad,” but having a high mold count, as measured by TYMC, is alarming and could be detrimental to both consumers and cultivators.
The vast majority of mold and yeast present in the environment are indeed harmless, and even useful to humans. Some fungi are used commercially in production of fermented food, industrial alcohol, biodegradation of waste material and the production of antibiotics and enzymes, such as penicillin and proteases. However, certain fungi cause food spoilage and the production of mycotoxin, a fungal growth by-product that is toxic to humans and animals. Humans absorb mycotoxins through inhalation, skin contact and ingestion. Unfortunately, mycotoxins are very stable and withstand both freezing and cooking temperatures. One way to reduce mycotoxin levels in a product is to have a low TYMC.
Yeast and mold have been found to be prevalent in cannabis in both current and previous case studies. In a 2017 UC Davis study, 20 marijuana samples obtained from Northern California dispensaries were found to contain several yeast and mold species, including Cryptococcus, Mucor, Aspergillus fumigatus, Aspergillus niger, and Aspergillus flavus.3 The same results were reported in 1983, when marijuana samples collected from 14 cannabis smokers were analyzed. All of the above mold species in the 2017 study were present in 13 out of 14 marijuana samples.4
Aspergillus species niger, flavus, and fumigatus are known for aflatoxin production, a type of dangerous mycotoxin that can be lethal.5 Once a patient smokes and/or ingests cannabis with mold, the toxins and/or spores can thrive inside the lungs and body.6, 7 There are documented fatalities and complications in immunocompromised patients smoking cannabis with mold, including patients with HIV and other autoimmune diseases, as well as the elderly.8, 9, 10, 11
For this reason, regulations exist to limit the allowable TYMC counts for purposes of protecting consumer safety. At the time of writing this article, the acceptable limit for TYMC in cannabis plant material in Colorado, Nevada and Canada is ≤10,000 CFU/g. Washington state requires a mycotoxin test.12 California is looking into testing for specific Aspergillus species as a part of their requirement. As the cannabis industry continues to grow and advance, it is likely that additional states will adopt some form of TYMC testing into their regulatory testing requirements.
Centre for Disease control and prevention. 2004 Outbreak of Aflatoxin Poisoning – Eastern and central provinces, Kenya, Jan – July 2004. Morbidity and mortality weekly report.. Sep 3, 2004: 53(34): 790-793
Cescon DW, Page AV, Richardson S, Moore MJ, Boerner S, Gold WL. 2008. Invasive pulmonary Aspergillosis associated with marijuana use in a man with colorectal cancer. Diagnosis in Oncology. 26(13): 2214-2215.
Szyper-Kravits M, Lang R, Manor Y, Lahav M. 2001 Early invasive pulmonary aspergillosis in a leukemia patient linked to aspergillus contaminated marijuana smoking. Leukemia Lymphoma 42(6): 1433 – 1437.
Verweii PE, Kerremans JJ, Voss A, F.G. Meis M. 2000. Fungal contamination of Tobacco and Marijuana. JAMA 2000 284(22): 2875.
Ruchlemer R, Amit-Kohn M, Raveh D, Hanus L. 2015. Inhaled medicinal cannabis and the immunocompromised patient. Support Care Cancer. 23(3):819-822.
McPartland JM, Pruitt PL. 1997. Medical Marijuana and its use by the immunocompromised. Alternative Therapies in Health and Medicine. 3 (3): 39-45.
Hamadeh R, Ardehali A, Locksley RM, York MK. 1983. Fatal aspergillosis associated with smoking contaminated marijuana, in a marrow transplant recipient. Chest. 94(2): 432-433.
Strictly Necessary Cookies
Strictly Necessary Cookie should be enabled at all times so that we can save your preferences for cookie settings.
We use tracking pixels that set your arrival time at our website, this is used as part of our anti-spam and security measures. Disabling this tracking pixel would disable some of our security measures, and is therefore considered necessary for the safe operation of the website. This tracking pixel is cleared from your system when you delete files in your history.
If you disable this cookie, we will not be able to save your preferences. This means that every time you visit this website you will need to enable or disable cookies again.