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The 3-Legged Stool of Successful Grow Operations: Climate, Cultivation & Genetics – Part 4

By Phil Gibson
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This is Part 4 in The 3-Legged Stool of Successful Grow Operations series. Click here to see Part 1, here to see Part 2, and here to see Part 3. Stay tuned for Part 5, coming next week.

Integrated Pest Management (IPM)

Aeroponic & hydroponic systems can operate with little to no soil or media. This eliminates the pest vectors that coco-coir, peat moss/perlite and organic media can harbor as part of their healthy biome approach. Liquid nutrient systems come at the nutrient approach from a different direction. Pure nutrient salts (nitrogen, potassium, magnesium and trace metals) are provided to the plant roots in a liquid carrier form. This sounds ideal for integrated pest management programs, but cultivators have to be aware of water and airborne pathogens that can disrupt operations. I will summarize some aspects to consider in today’s summary.

The elimination of soil media intrinsically helps a pest management program as it reduces the labor required to maintain a grow and the number of times the grow room doors are opened. Join that with effective automation with sensors and software, and you have immediate improvements in pest access. Sounds perfect, but we still have staff to maintain a facility and people become the number one source of contamination in a grow operation.

Figure 1: Example of Pythium Infected & Healthy Roots

Insects do damage directly to plants as they grow and procreate in a grow room. They also carry other pathogens that infect your plants. For example, root aphids, a very common problem, are a known carrier of the root pathogen, Pythium.

Procedures

One of the most common ways for pests to access your sealed, sterile, perfectly managed facilities are in the root stock of outsourced clones. If you must start your grow cycles with externally sourced clones, it is strongly recommended that you quarantine those clones to make sure that they do not import pest production facilities into your operation. Your operation management procedures must be complete. If you take cuttings from an internal nursery of mother plants, any pathogens present in your mother room will migrate through cuttings into your clones, supply lines, and subsequently, flower rooms.

Figure 2: Healthy Mothers & Clones, Onyx Agronomics

Start your gating process with questioning your employees and visitors. Do they grow at home or have they been to another grow operation in the last week? In the last day? You may be surprised by how many people that gain access to your grow will answer these questions in the affirmative.

Developing standard operating procedures (SOPs) that are followed by every employee and every visitor will significantly reduce your pest access and infection rates, and hence, increase your healthy harvests and increase your profitability. Procedures should include clothing, quarantining new genetics and cleaning procedures, such as baking or irradiating rooms to guarantee you begin with a sterile facility. This is covered more in the complete white paper.

Engineering Controls

Figure 3: Access Control: Air Shower, FarmaGrowers

Technology is a wonderful thing but no replacement for regimented procedures. Considered a best practice, professional air showers, that bar access to internal facilities, provide an aggressive barrier for physical pests. These high velocity fan systems and exhaust methods blow off insects, pollen and debris before they proceed into your facility. From that access port into your grow space, positive air flow pressure should increase from the grow rooms, to the hallways, to the outside of your grow spaces. This positive airflow will always be pushing insects and airborne material out of your grow space and away from your plants.

Maintaining Oxidation Reduction Potential (ORP)

ORP is a relative measurement of water health. Perfect water is clear of all material, both inert and with life. Reverse osmosis (RO) is a standard way to clear water but it is not sufficient in removing microscopic biological organisms. UV and chemical methods are needed in addition to RO to clear water completely.

ORP is an electronic measurement in millivolts (mV) that represents the ability of a chemical substance to oxidize another substance. ORP meters are a developing area and when using a meter, it is important to track the change in ORP values rather than the absolute number. This is due to various methods that the different meters use to calculate the ORP values. More on this in the white paper.

Oxidizers

Figure 4: AEssenseGrows Aeroponic Nozzles

There are two significant ways to adjust the ORP of a fertilizer/irrigation (fertigation) solution. The first is by adding oxidizers. Examples are chemical oxidizers like hydrogen peroxide (H2O2), hypochlorous acid (HOCl), ozone (O3) and chlorine dioxide (ClO2). Adding these to a fertigation solution increases the ORP of the fertigation solution by oxidizing materials and organic matter. The key is to kill off the bad things and not affect the growth of plants. Again here, the absolute ORP metric is not the deciding factor in the health of a solution and the methods by which each chemical reaction occurs for each of these chemicals are different. This is compounded by the fact that different ORP meters will show different readings for the same solution.

Another wonderful thing about automation and aeroponic and hydroponic dosing systems is that they can automatically maintain oxidizing rates and our white papers explain the methods executed by today’s automation systems.

Water Chilling

Another way to adjust ORP is to reduce the water temperature of the reservoirs. Maintaining water temperature below the overall temperature of your grow rooms is imperative for minimal biological deposition and nutrient system health. Water chillers use a heat exchanger process to export heat from liquid nutrient dosing reservoirs and maintain desired temperatures.

The benefit of managing ORP in aeroponic and hydroponic grow systems is highly accelerated growth. This is enhanced in aeroponics due to the effectively infinite oxygen exchanging gases at the surface of the plant roots. Nutrient droplets are sprayed or vaporized in parallel and provided to these root surfaces. Maximizing the timing and the best mineral nutrients to the root combustion is the art of grow recipe development. Great recipes drive superior yields and when combined with superior genetics and solid environmental controls, these plants will deliver spectacular profits to a grow operation.

Another Hero Award

Before closing this chapter, we have many cultivators that are producing stellar results with their operational and IPM procedures, so it is hard to choose just one leader. That said, our hats are off to RAIR Systems again and their director of cultivation, Ashley Hubbard. She and her team are determined to be successful and drive pests out of their operations with positive “little critters” and the best water treatment and management that we have seen. You are welcome to view the 7-episode walkthrough of the RAIR facility and their procedures here.

To download the complete guide and get to the beef quickly, please request the complete white paper Top Quality Cultivation Facilities here.

Stay tuned for Part 5 coming next week where we’ll discuss Genetics.

The 3-Legged Stool of Successful Grow Operations: Climate, Cultivation & Genetics – Part 1

By Chris Wrenn, Phil Gibson
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Ideal cannabis profits come from high demand/high selling prices and low production costs. The spread between those two, or margin, can determine the life or death of your business. We want to share this series of articles so that your next investment can be highly successful and high margin out-of-the-box.

Regardless of the grow method (soil, coco, rockwool, hydro or aero), every plant performs best in its own ideal environmental conditions. Experienced growers gained success through hard work, and just that, experience. Many have tried more advanced grow technologies, but shied away due to early trial failures or the complexity of maintaining chemistry across a grow facility. The wonderful thing now is that precision sensors and software controls eliminate the risk to robust healthy plants and harvest success. Growers are now able to both manage production while performing research in line with their operations.

We have learned a great deal working with our grow partners over the last 6 years. Every grow facility and location are different due to local weather, business environment and scale. This series of articles and guide, authored by our expert, Christopher Wrenn, will include recommendations of the most successful approaches we have seen here in North America and all over the world.

A 4-Layer fully aeroponic flower room using movable racking systems

Building top-quality cultivation facilities is no simple task. Cultivators are also looking for new help as they shift from older soil or media approaches to more efficient grow methods. One powerful method is aeroponics, which is very good at growing any type of plant in air in a sterile environment, with labor, nutrient and water savings.

Where possible, we will share key vendors that support healthy grow operations and (since it is World Series Time), customer examples that are knocking it out of the park. In today’s competitive business environment, it is critical to do what we can to increase profitability and survival in the face of steep headwinds. We want you to crush it and be “the last man standing.”

So, let’s get to it.

Climate: Environmental Control

We begin with a critical leg in your environment. The process of photosynthesis is more than just light, plant and moisture. We want to do more than just grow plants. We want to grow highly profitable plants. That means we have to accelerate photosynthesis so we are growing faster, bigger and more potent than our competitors.

The Vapor Pressure Deficit (VPD) is the amount of “drying power” available in the air surrounding your plants. This is a useful way to understand the amount of moisture your atmosphere can remove from your plants as they digest carbon dioxide and aspirate water and oxygen into the air around your plants. A higher vapor deficit is a good thing for growth; It is also a measurement of how much nutrient you can uptake into the plant roots and convert into size and potency in the canopy. We recommend that you have resources in your grow rooms to maintain your environment to within 5% of both your humidity and temperature targets for ideal results.

Onyx Agronomics is a Tier 3 indoor cultivator in the State of Washington. This is the canopy in one of their 8 flower rooms.

In our Top Quality Cultivation Facility white paper, we review environmental settings for temperature and humidity for mother, clone/veg and flower rooms for day and night light cycles from early cuttings through to end of harvest flush. Day temperatures can be up to 20% higher than night temperatures for example.

Cooling

Managing temperature may seem straight-forward but the heat generated by LED lights, HPS lights or the sun will vary across rooms, time exposure and with the distance of the light source from the plants. Measurement sensors should be distributed across rooms to monitor and trigger temperature resources.

Humidification/Dehumidification

This is a topic that can be underappreciated by cultivators. It is important to slowly transition humidity as you move plants from cuttings to clones, to veg and to flower. Beginning in a very humid stage to motivate root start, humidity will be stepped down from an opening near 90% down to an arid 50% in your end of flush flower rooms. We detail the transitions in 5% increments in the white paper.

The 4-Layer aeroponic flower room with movable racking systems from the side with a tall human for scale. One can do a lot with 30′ ceilings.

Relative Humidity (RH) and the related VPD are the key metrics to accelerating growth throughout the stages. Not sizing dehumidifiers correctly is one of the most common mistakes our grow partners learn about as they move to full production. In the first phase of turning cuttings from healthy mothers into rooted clones, hitting your target VPD to motivate root growth is the number one success factor. This will require the addition of humidity into your clone room. It is also typical to require raise the humidity of your flower rooms when you transition clone/veg plants from the high humidity clone/veg room into an initially dry flower room, otherwise the plants may go into shock as a result of the dramatic change.

As flowering begins, if humidity remains high, and the VPD is below target, the plants will not be moving nutrients and transpiring moisture. We have seen lowering the humidity from 70% in a flower room down to 50%, results in a yield increase from 50 grams to 90 grams of dry trim bud per plant, so a smooth transition can both accelerate growth and have a big impact on your margins and profitability.

Plants in aeroponics can truly have explosive growth. This means that they will also transpire moisture at an accelerated rate. Fast automated growth in aeroponics means increased humidity output. Sizing these critical systems for humidification/dehumidification are a critical part of the design process.

Airflow

Fans combined with your cooling/heating/humidity/dehu systems need to mix the air in a room to break the boundary layer at the leaf surface for transpiration. As we covered, VPD is critical to growth success. A dry surface motivates the plants to transpire moisture. We recommend flow rates across the canopy in a 0.5-1.5 meter/second rate to align to your genetics and where you are in the flowering process.

A raw facility before it gets outfitted.

Airflow and flowering means rich beautiful aromas are generated. Every facility has to consider odor control. If you are in a populated area, you will have ordinances and neighbors to satisfy. The best way to do this is to minimize the amount of air that exits a facility. This is also the cheapest approach.

Sterile HEPA filters and scrubbing systems clean air of pathogens and odor but they also need to circulate and “condition” air to the correct temperature and humidity levels before it can be recirculated into a room. Oftentimes, this is a good place to also recapture humidity and reinject it into your pure water cleaning systems.

Key vendors to talk to about sizing air treatment systems are SURNA, Quest, Desert Aire and AGS. Each of these vendors have specialties and tend to be superior partners in different regions of the world. We would be happy to introduce you to excellent support resources for air management systems.

To download the complete guide and get to the beef quickly, please request the complete white paper Top Quality Cultivation Facilities here.

Click here to see Part 2 where we discuss water quality and management.

Your Cultivation Plan is the Most Important Factor to Increase Your Yield

By David Perkins
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Having a well-built grow room with adequate lighting, the ability to properly control the environment, proper nutrient feedings, a good pest management plan, well trained employees and an experienced cultivation manager are very important to the overall output of cannabis plants. However, even if you have all those measures in place, there’s no guarantee of success. One factor that is often overlooked is how many harvests you can get per year, as clearly the more harvests you can get in a given time period, the more likely your chances of success are in this competitive industry. This is why having a good cultivation plan in place, with proper foresight and planning, is so essential to success.

Increasing yield or production output in a cannabis cultivation facility can often be as simple as having the right cultivation plan in place to ensure that you are harvesting the maximum number of times per year. All it requires is a well thought out plan, and best of all, that does not cost any money if you have someone with enough cultivation experience assisting you and will earn back more than the cost of paying a consultant to get such a plan in place.

In this article I will explain why changing nutrients, grow media or even a cultivation manager may not necessarily increase yield, quality or your chance of success. What you should be focusing on is your cultivation plan and the scheduling of your cultivation cycles.

  1. Why changing nutrient companies may not necessarily increase your yield
Nutrient dosers are used to inject fertilizer directly into irrigation lines

For the most part, nutrient companies use the same ingredients in their product lines and often buy them from the same source, but they combine them in different forms and ratios to create their “unique” product. You can go to a grow store, pick five different nutrient products, read the labels and compare the different nutrients in each one. You will find for the most part that they are very similar. Generally speaking, you could pick any one of those five nutrient companies and have great results. Mixing nutrients into a nutrient tank needs to be done precisely and if your employees are not doing it properly this can lead to plant health issues. In larger cultivation facilities, often nutrient dosers are used to inject fertilizer into the irrigation lines without having to mix nutrients. However, if the dosers are not set to the proper ratios, this can also lead to plant health issues.

There are a few companies that I really like that have a different approach to plant nutrition, which saves time and can prevent human error associated with mixing and applying liquid nutrients. Soilscape solutions, Organics Alive and Beanstock Agriculture all have nutrient lines that are intended to be used with soil or soilless media that can be amended into the soil which provide a slow steady release of nutrients that the plants can uptake as needed. This avoids the risk of human error in repeatedly applying liquid nutrients to the plants.

  1. Why changing grow medium and nutrients will not necessarily improve your yield but may increase yourquality

Whether it is rock wool, coco fiber, a soilless mix or living soil, everything has a limit. Giving your plants the proper amount of water and the frequency at which you water, along with having sufficient room for the roots to grow are key factors to ensuring plant health. If your plants aren’t getting watered properly, no matter what media you are growing in, you will be having problems. Changing things like grow media won’t result in instant success, as there will always be a learning curve when making changes to your cultivation. If you cannot adapt quickly enough, you can quickly create major problems.

plebanisoil
Changing things like grow media won’t result in instant success, as there will always be a learning curve when making changes to your cultivation.

You would be better off to master the grow media you are currently working; you will have more chance of success making slight alterations to your current media than you will if you switch your grow media altogether. There are so many different nutrient lines, soil companies, coco coir companies and the truth is any of them can lead to success.

Changing grow media and nutrients do play a large role in quality though. With cannabis being legalized in many states, the overall quality of cultivation inputs have increased, especially nutrients. However, in general, with some exceptions, the quality of cannabis has not necessarily increased along with the increase in quality of nutrients. One exception: I would argue that switching from salt nutrients and rock wool, to organic living soil will result in an improvement to the flavor, quality and terpenes of the cannabis.

A lot of people use rock wool with salts because it’s easier to scale up than if you are growing in soil, but some quality is also sacrificed. Soil is heavy and messy and most people throw their soil away which takes a lot of money and labor to do. Reusing your soil is one of the best ways to save time, money and increase quality. I had a friend that grew the same variety, same lights, same ventilation but grew hydroponically with salt-based nutrients and he would always say the cannabis I grew, organically, tasted better. The same was true when we grew the same variety outdoors. He used salt-based fertilizer, I used amended soil with water. There wasn’t really a comparison in flavor and the yield was not compromised either! This was his opinion not mine.

I think the vast majority of consumers have not seen the type of quality that someone in Northern California who has been smoking and growing for 20 plus years has seen. Quality is relative to what you have been able to acquire. Most people especially nowadays will never see the quality that used to be common when we didn’t treat the sacred herb like a commodity. When you do it for the love of the plant it shows. Remember, quality is relative to your experience and if salty weed is all you know, you are probably missing out.

  1. Why changing your Cultivation manager may not necessarily increase your yield

Every cultivation facility should have an experienced cultivation manager who is knowledgeable in the areas of nutrient requirements, pest management, environmental requirements, managing employees and overall facilities operations. If a grow room cannot sustain the proper environmental set points, blaming the problems and issues that arise on the cultivation manager is not fair. It is a common problem in the cannabis industry – the owners of a company are not seeing the results that they want and think that by replacing the cultivation manager it will solve all their problems. In reality, often the problem results from upper management or owners of the company not providing the cultivation manager the tools necessary to perform their job at the highest level. Another common problem is when owners fire the cultivation manager and replace them with lower-level employees to manage the facility. The problem with this is those employees do not have enough experience nor the attention to detail to successfully run a cultivation facility. The result is that yield and quality suffer tremendously.

  1. You should be harvesting every 60-70 days
If you are cultivating strains that finish flowering in 60 to 70 days you should be getting five harvests per year.

The reality is there is no one specific thing you can try or buy that will result in success. It is everything combined, the HVAC system, lights, genetics being grown, water quality, air quality, root zone temperature, ability to control environment, having a clean facility, disease free plants, knowledgeable cultivation manager etc. that are required to operate a successful cultivation.

But all of that is less important to yield than a good cultivation plan. Cultivation methods directly tie into the overall production of a facility. But, regardless of whether you’re growing in soil, hydroponics, using LED or HPS, have low or high plant counts, if you don’t have the ability to harvest a grow room, clean and replant within a very short amount of time (ideally one or two days) then you’re going to be losing out on profit.

If you’re cultivating strains that finish flowering in under 60 days you should be getting six harvests per year. If you are cultivating strains that finish flowering in 60 to 70 days you should be getting five harvests per year. To do this, you will need to have the appropriate amount of plants that are ready to be flowered to refill your grow room or greenhouse ready to flower. With a little bit of planning and foresight you will be able to do this, and you will be on your way to producing your highest yield potential.

If you are struggling to have enough plants that are ready to flower once you are done harvesting and cleaning your grow room, having trouble planning your cultivation schedule to maximize production, or struggling to maintain a mother and clone room to supply your own plants or planning for the appropriate amount of labor, contact Floresco Consulting and talk with one of our cultivation advisors to get you back on track. We can guide you to ensure you are harvesting, cleaning and replanting every 60 days. Contact us today to get your facility producing at its maximum potential.

Flower-Side Chats Part 3: A Q&A with Harvey Craig, CEO Harvey’s All Naturals and Co-Founder of Boot Ranch Farms

By Aaron Green
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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.

Harvey Craig, CEO Harvey’s All Naturals and co-founder of Boot Ranch Farms

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!

Craig: Thank you very much!

5 Factors to Keep in Mind When Entering the Regulated Market

By David Perkins
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It’s a different world growing cannabis in California- in fact, it’s a completely different experience than it was even four years ago. It can be overwhelming to begin the process, which is where an experienced cultivation consultant can help. This article will highlight 5 factors to keep in mind before you begin growing in California’s regulated recreational market.

Start Up – Costs, needs & endless variables

So you’ve decided to begin a recreational grow, here are the factors to consider before you get started.

Permitting, the necessary pre-cursor to cultivation, can be time- consuming, extremely expensive, and overwhelming. General experience dictates that any grow will take longer than planned and cost way more money than you ever expected or anticipated. Always account for more money and time than you think you need. Working with an experienced consultant can help you plan and account for all the costs and variables you may not have considered, prior to beginning cultivation, in order to ensure your success.

Understand that growing boutique style cannabis is very difficult on a large scale, consistently.

Equipment. When choosing what equipment to use, stick to reputable equipment manufacturers. Don’t just go with the latest high-tech gear because you see it on Instagram being advertised by a big, fancy grow operation. Stick to what you know best. Do your homework and research the equipment as much as possible, prior to purchase. Use equipment that has been tested and well documented with success. Some questions to ask yourself: is this necessary? Is it cost effective? Will it help me reach my goals?

Grow your business slowly and naturally. Getting too big too quick will most likely expose inefficiencies in your operating plan, which will be further compounded when production increases. Don’t sink before you can swim and start out on a massive scale before you have perfected your process.

Cultivation – It pays to design it right the first time

Success begins in the grow room. Never forget that. A properly engineered cultivation plan can be the difference between 3 and 6 harvests per year. Again, it is imperative here to do your homework. A well-thought-out plan can make or break you, and that is where an experienced cultivation consultant can help.

Set realistic expectations. Understand that growing boutique style cannabis is very difficult on a large scale, consistently. Don’t expect to grow perfect cannabis every time – it is unrealistic and can ultimately lead to failure if your financial model depends on it. Growing a plant, while mostly in your control, involves too many variables to rely on a perfect outcome round after round. You can do everything in your power, yet something unexpected can still happen and be detrimental to your yield, and therefore your profit. You must expect and plan for this.

Automating as much of your grow as possible is always a good idea. This will greatly reduce labor costs and more importantly, minimize human error. In some instances, it will even allow you to review data and information remotely, in real time, allowing you to ensure your cultivation site is always running as efficiently as possible, even when you aren’t there.

Processing – Don’t skimp on the process

If you are going to be harvesting cannabis for flower, it is imperative to have a properly built facility for drying, curing and storing your product. You must consider that this building will need to be large enough to house and properly store all of your harvest at once. This can make or break your crop at harvest time. If you don’t have the capacity to handle your harvest properly, it can lead to disastrous issues such as mold or too quick of a cure – conditions which make your cannabis unsellable in the regulated market.

dry cannabis plants
Rows of cannabis plants drying and curing following harvest

Although costly, if done correctly, you can also design this area to serve as your propagation, trimming, and breeding areas, which will ultimately save on costs in the long run.

Also keep in mind, hand trimmed cannabis will always look more appealing to the consumer than machine trimmed cannabis. However, hand trimming can be time-consuming, labor-intensive, and therefore far more costly than machine trimming. These are factors you will need to consider and budget for when deciding how to proceed. If you use a machine, you may save money up front, but will you be able to sell your cannabis at full price?

Distribution – Have a plan

It is a good idea to have a plan for distribution, prior to start up. If you have an agreement with a retail outlet (or contract with a distributor) in writing, you will protect yourself from financial failure. Cannabis will never grow more valuable over time, therefore, you want to have a plan in place for distribution, as soon as the cannabis is harvested and processed. Just as was the case in the black-market days, you never want to hold on to your cannabis for long periods of time.

Do not distribute without agreements in writing! While some oral agreements may be enforceable, it will be extremely costly to litigate. Therefore, you should plan to hire a lawyer beforehand to create fail-proof agreements that will hold up in court, should a distributor not pay you for your product.

Sales – Build your brand, but be realistic

Building your brand is important. And if you don’t produce your own high-quality flower you cannot expect to have a product up to your standards. Your brand will not be successful if you cannot consistently provide consumers with high quality cannabis. Relying on other growers to produce your cannabis for you is risky to your brand. Even if you are a manufacturer, you may not be able to rely on other suppliers to maintain the quality volume you need in order to manufacture your products consistently.

The regulated market in California is new. Therefore you must necessarily account for a great degree of price fluctuations in the market. When creating your budget at the outset, you must account for fluctuations in profit. Knowing when prices are going to be at their lowest can help you avoid having an oversupply of inventory. It can also help you avoid such situations by planning your cultivation/harvest accordingly.

There are both consumer and government influenced market trends that can affect your bottom line. These must be accounted for at the outset.

On the consumer level, you must know what people are buying and how they are consuming. And these factors can change quickly with the introduction of new technology, methods or new devices intended for cannabis consumption. You must stay on top of these trends.

The government regulations can also affect these trends. Products used for cultivation can become banned, i.e. products you once relied on in your cultivation can be found to have contaminants known to cause test failures, even in “approved products.”

Ultimately, all of these factors can make or break your success, and therefore, must be considered, researched and accounted for prior to beginning your cultivation in the regulated market. Working with a consultant with over 20 years of grow experience, and more importantly, extensive experience in large scale cultivation in the regulated market, can help you achieve the success you desire. Cultivation in the regulated market is costly, but working with a consultant can help you cut costs at the outset, and save you from unexpected expenses in the long run.

Large Scale Cultivation Planning: 4 Important Factors to Consider

By David Perkins
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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.

1. Genetics

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.

Larger scale cultivation requires bigger and more expensive equipment.

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.

3. Nutrients

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.

Controlling your clone supply can ensure they are healthy

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.

dry cannabis plants

How to Grow Cannabis Plants for Concentrate Production

By Andrew Myers
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dry cannabis plants

While flower is still the most popular way to consume cannabis, the concentrates market is booming. Some predict concentrates will be nearly as popular as flower by 2022, with an estimated $8.5 billion in retail sales. That’s a lot of concentrates and, chances are, cannabis producers are already feeling the pressure to keep up.

Concentrates refer to products made from processing cannabis – often resulting in much higher THC or CBD percentages. The category includes oils, wax, dabs, shatter, live resin and hash. Consumers are increasingly drawn to these cannabis products for their near-immediate and intense effects. They’re often consumed through vaporization, dabbing or sublingual absorption and are sometimes favored by those who want to avoid smoking. Cannabis growers who have traditionally focused on flower yields may decide to prioritize quality and potency levels in order to tap into these changing consumer tastes.

What Growers Should Focus on to Produce High Quality Concentrates
We’ll let you in on a little secret: making good concentrates starts with good flower. If you’re starting with low-quality flower, it’s impossible to create a high-quality concentrate. Whatever qualities inherent to the flower you’re starting with will be amplified post-processing. So, really, the concentrate-making process starts at the seedling level, requiring the right care and attention to coax out the results you’re looking for.

Tetrahydrocannabinol (THC), just one of hundreds of cannabinoids found in cannabis.

But what makes good flower? While this can be a subjective question, those producing concentrates generally look for flowers with big, abundant trichomes. Trichomes are the small, dewy structures found across the cannabis plant on buds, leaves and even the stem. They’re responsible for producing the plant’s cannabinoids and terpenes – the chemical compounds that give a strain its unique benefits, aroma and taste. Evolutionarily, trichomes attract pollinators, deter hungry herbivores and provide some defense against wind, cold and UV radiation.

Generally, trichomes indicate how potent the flower is. Plus, what we’re most often looking for when making concentrates is higher cannabinoid and terpene profiles, while also ensuring absolute safety.

What measures can growers take to produce crops that are ideal for concentrate production? Start with the following:

Avoiding Contaminants
Just like you would wash your fruits and vegetables before consumption, consumers want to be sure there’s no dangerous residuals in the concentrate they are ingesting. Growers can avoid any post-process residuals by taking a few key steps, including:

  • Photo: Michelle Tribe, Flickr

    Cutting out the pesticides. Any pesticides that are on your flowers before they go through processing will show up in your concentrates, often even more – you guessed it – concentrated. This is a serious health concern for consumers who might be sensitive to certain chemicals or have compromised immune systems. It’s dangerous to healthy consumers, too. Rather than spraying hazardous chemicals, growers could consider integrated pest management techniques, such as releasing predatory insects.

  • Limiting foliar spraying. Some growers will use foliar spraying to address nutrient deficiency or pest-related issues through delivering nutrients straight to the leaves. However, this can also result in contaminated concentrates. If you really need to spray, do it during the vegetative stage or investigate organic options.
  • Taking the time to flush the crop. This is a critical step in reducing potential contaminants in your concentrate, especially if you’re using a non-organic nutrient solution or fertilizer. Flushing simply means only giving your plants water during the final two weeks of flowering before harvest, resulting in a cleaner, non-contaminated flower and therefore a cleaner concentrate.

Perfecting the Indoor Environment
When cultivating cannabis indoors, growers are given ultimate control over their crop. They control how much light the plants receive, the lighting schedule, temperature and humidity levels. Creating the ideal environment for your cannabis crop is the number one way to ensure healthy plants and quality concentrates. There are many factors to consider when maintaining an indoor grow:

  • Temperature regulation. Trichomes are sensitive to temperature changes and start to degrade if they’re too hot or too cold. To maintain the best trichome structure, you’ll want to maintain an ideal temperature – for most strains, this falls between an idyllic 68 and 77 degrees.
  • Adequate light. For plants to perform photosynthesis indoors, they’ll need an appropriate light source – preferably one that is full-spectrum. Full-spectrum LEDs are able to closely replicate the sun and provide ample, uniform light to your crop. Another selling point for LEDs is their low heat output, making it much easier for growers to regulate ambient heat.

    dry cannabis plants
    Rows of cannabis plants drying and curing following harvest
  • CO2. Another necessary ingredient for photosynthesis is CO2. Providing your indoor crops with CO2 can boost plant size and yields and, therefore, provides more surface area for trichomes to develop and thrive.
  • Cold snap prior to harvest. Some growers rely on this age-old tactic for one last push before harvest – lowering their temperature for a few days right at the end of the flower cycle. They believe this puts the plants into a defense mode and will produce more trichomes in order to protect themselves.

Following Best Practices Post-Harvest
You made it to harvest – you’re almost done!

When harvesting and storing your plants, handle them with care to reduce damage to trichomes. If you’re planning on immediately making concentrates, you can move forward to the drying and curing process. If you’re going to wait a few weeks before processing, freeze your plants. This will preserve the cannabinoid and terpene profiles at their peak.

As the cannabis industry continues to expand, more consumers are likely to reach for concentrates at their local dispensaries. It makes sense that businesses want to diversify their offerings to satisfy customers looking for the most effective way to consume cannabis. As with any cannabis-derived product, producers will want to prioritize quality and safety – especially in the concentrate market.

Microbiology 101 Part Two

By Kathy Knutson, Ph.D.
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Microbiology 101 Part One introduced the reader to the science of microbiology and sources of microbes. In Part Two, we discuss the control of microorganisms in your products.

Part 2

The cannabis industry is probably more informed about patients and consumers of their products than the general food industry. In addition to routine illness and stress in the population, cannabis consumers are fighting cancer, HIV/AIDS and other immune disorders. Consumers who are already ill are immunocompromised. Transplant recipients purposely have their immune system suppressed in the process of a successful transplant. These consumers have pre-existing conditions where the immune system is weakened. If the immunocompromised consumer is exposed to viral or bacterial pathogens through cannabis products, the consumer is more likely to suffer from a viral infection or foodborne illness as a secondary illness to the primary illness. In the case of consumers with weakened immune systems, it could literally kill them.Bacteria, yeast, and mold are present in all environments.

The cannabis industry shoulders great responsibility in both the medical and adult use markets. In addition to avoiding chemical hazards and determining the potency of the product, the cannabis industry must manufacture products safe for consumption. There are three ways to control pathogens and ensure a safe product: prevent them from entering, kill them and control their growth.

Prevent microorganisms from getting in

Think about everything that is outdoors that will physically come in a door to your facility. Control the quality of ingredients, packaging, equipment lubricants, cleaning agents and sanitizers. Monitor employee hygiene. Next, you control everything within your walls: employees, materials, supplies, equipment and the environment. You control receiving, employee entrance, storage, manufacturing, packaging and distribution. At every step in the process, your job is to prevent the transfer of pathogens into the product from these sources.

Kill microorganisms

Colorized low-temperature electron micrograph of a cluster of E. coli bacteria.
Image courtesy of USDA ARS & Eric Erbe

The combination of raw materials to manufacture your product is likely to include naturally occurring pathogens. Traditional heat methods like roasting and baking will kill most pathogens. Remember, sterility is not the goal. The concern is that a manufacturer uses heat to achieve organoleptic qualities like color and texture, but the combination of time and temperature may not achieve safety. It is only with a validated process that safety is confirmed. If we model safety after what is required of food manufacturers by the Food and Drug Administration, validation of processes that control pathogens is required. In addition to traditional heat methods, non-thermal methods for control of pathogens includes irradiation and high pressure processing and are appropriate for highly priced goods, e.g. juice. Killing is achieved in the manufacturing environment and on processing equipment surfaces after cleaning and by sanitizing.

If you have done everything reasonable to stop microorganisms from getting in the product and you have a validated step to kill pathogens, you may still have spoilage microorganisms in the product. It is important that all pathogens have been eliminated. Examples of pathogens include Salmonella, pathogenic Escherichia coli, also called Shiga toxin-producing E. coli (STEC) and Listeria monocytogenes. These three common pathogens are easily destroyed by proper heat methods. Despite steps taken to kill pathogens, it is theoretically possible a pathogen is reintroduced after the kill step and before packaging is sealed at very low numbers in the product. Doctors do not know how many cells are required for a consumer to get ill, and the immunocompromised consumer is more susceptible to illness. Lab methods for the three pathogens mentioned are designed to detect very low cell numbers. Packaging and control of growth factors will stop pathogens from growing in the product, if present.

Control the growth of microorganisms

These growth factors will control the growth of pathogens, and you can use the factors to control spoilage microbes as well. To grow, microbes need the same things we do: a comfortable temperature, water, nutrients (food), oxygen, and a comfortable level of acid. In the lab, we want to find the pathogen, so we optimize these factors for growth. When you control growth in your product, one hurdle may be enough to stop growth; sometimes multiple hurdles are needed in combination. Bacteria, yeast, and mold are present in all environments. They are at the bottom of the ocean under pressure. They are in hot springs at the temperature of boiling water. The diversity is immense. Luckily, we can focus on the growth factors for human pathogens, like Salmonella, pathogenic E. coli, and Listeria monocytogenes.

The petri dishes show sterilization effects of negative air ionization on a chamber aerosolized with Salmonella enteritidis. The left sample is untreated; the right, treated. Photo courtesy of USDA ARS & Ken Hammond

Temperature. Human pathogens prefer to grow at the temperature of the human body. In manufacture, keep the time a product is in the range of 40oF to 140oF as short as possible. You control pathogens when your product is at very hot or very cold temperatures. Once the product cools after a kill step in manufacturing, it is critical to not reintroduce a pathogen from the environment or personnel. Clean equipment and packaging play key roles in preventing re-contamination of the product.

Water. At high temperatures as in baking or roasting, there is killing, but there is also the removal of water. In the drying process that is not at high temperature, water is removed to stop the growth of mold. This one hurdle is all that is needed. Even before mold is controlled, bacterial and yeast growth will stop. Many cannabis candies are safe, because water is not available for pathogen growth. Packaging is key to keep moisture out of the product.

Nutrients. In general, nutrients are going to be available for pathogen growth and cannot be controlled. In most products nutrients cannot be removed, however, recipes can be adjusted. Recipes for processed food add preservatives to control growth. In cannabis as in many plants, there may be natural compounds which act as preservatives.

Oxygen. With the great diversity of bacteria, there are bacteria that require the same oxygen we breathe, and mold only grows in oxygen. There are bacteria that only grow in the absence of oxygen, e.g. the bacteria responsible for botulism. And then there are the bacteria and yeast in between, growing with or without oxygen. Unfortunately, most human pathogens will grow with or without oxygen, but slowly without oxygen. The latter describes the growth of Salmonella, E. coli, and Listeria. While a package seals out air, the growth is very slow. Once a package is opened and the product is exposed to air, growth accelerates.

Acid. Fermented or acidified products have a higher level of acid than non-acid products; the acid acts as a natural preservative. The more acid, the more growth is inhibited. Generally, acid is a hurdle to growth, however and because of diversity, some bacteria prefer acid, like probiotics which are non-pathogenic. Some pathogens, like E. coli, have been found to grow in low acid foods, e.g. juice, even though the preference is for non-acidic environments.

Each facility is unique to its materials, people, equipment and product. A safe product is made by following Good Agricultural Practices for the cannabis, by following Good Manufacturing Practices and by suppressing pathogens by preventing them coming in, killing them and controlling their growth factors. Future articles will cover Hazard Analysis and Critical Control Points (HACCP) and food safety in more detail.