Tag Archives: irrigate

Soapbox

Clean Grow Still Failing? Check for Endophytic Mold

By Bernie Lorenz, PhD
No Comments

The journal Frontiers in Plant Science recently shared an important article from researchers at Simon Fraser University in British Columbia, highlighting the “Pathogens and Molds Affecting Production and Quality of Cannabis Sativa.”

As a chemist focused on the science of preventing and mitigating mold in greenhouse and indoor cannabis grow facilities, this piece was fascinating to me. Like many others, it details and explains prevalent mold like Penicillium, Cladosporium and Aspergillus – things I see in grows every day.

But wait, there’s more fungi

The research and resulting article also brought up another type of fungi – endophytic mold. Endophytic mold usually lives symbiotically with plants, or is at least beneficial for both plant and fungi.

But not always.

In the past, the industry has believed that damaging mold spores were found on the outside of the flower. When moved, that flower would release the spores and send them flying – often creating massive cross-contamination issues for indoor grows.

Hope Jones, PhD, CEO of Adivina & ECS

“While cannabis is an incredibly powerful plant in terms of its medicinal properties, it is unfortunately highly susceptible to many pest and pathogens,” says Hope Jones, PhD, CEO, Adivina & ECS. “And it is this susceptibility that is so challenging to many inexperienced or undisciplined grow operations.”

Now, however, we know that there’s another culprit to add to the list: the inner parts of the plant can also be a source of endophytic cross contamination and mold.

Since it grows inside of the plant, this fungus creates high spore counts that can cross contaminate from outside, into the flower.

Treating mold in a facility

Here’s the good news:

This seemingly bad news – that there’s a new fungus to worry about, and it is inside the flower – may actually help cannabis grows struggling with mold, and those who are following the proper protocols already.

A petri dish of mold growth from tested cannabis Photo credit: Steep Hill

Effective mitigation protocols can include things like treating HVAC systems, controlling humidity, using products like chlorine dioxide to treat irrigation lines, enforcing protective clothing and shoe covers for employees, reducing the amount of in-and-out for employees around grow rooms.

These are important upstream and environmentally-focused integrated pest management (IPM) programs that will usually keep facilities clean and relatively mold-free.

But if these programs are in place, and there’s still an issue, Endophytic fungi may be to blame.

If you are having ongoing mold issues but have ruled out cross-contamination and a facility without proper protocol, look to the mother plant.

“Small mistakes in agricultural practices are amplified with cannabis,” Dr. Jones continues. “And today’s propagation practices of traditional cloning add to this vulnerability. Cannabis is an annual plant and by keeping mothers in a perpetual state of vegetative growth for years, and taking repetitive cuttings produces clones in a highly stressed state. This stressed state diminishes genetic potential and weakens a plant’s ability to fight disease and pests.”

Testing for and addressing endophytic fungi

If these concerns are ringing a bell, remember, there is also a way to test for Endophytic mold.

Checking cuttings from suspected mother plants over a period of time is the best way to see if the Endophytic mold is present.

A section of the mother plant cutting is placed into a solution (for example, as outlined by the article, a very concentrated hypochlorite followed by 70% Ethanol) that will kill all of the microorganisms that are present on the surface of the plant tissues.

A large tissue culture facility run in the Sacramento area that produces millions of nut and fruit trees clones a year.

From there, an unadulterated dissection of the internal tissues can be extracted and cultured for quantification and identification of endophytic fungi.

“Tissue culture offers a form of genetic rebooting returning the plant to its natural genetic potential and thereby strengthening its natural ability to defend against environment assault,” says Dr. Jones. “It also allows the breeder to conduct pathogenic disease testing which provides the entire industry with a higher level of scientific certainty and analysis.”

If you find this mold inside of the mother plant, your facility’s mold problem could be a systemic issue, not an environmental one.

If you do find that Endophytic mold is causing issues, of course, you may have to destroy the mother plant.

This should not mean the end of a strain. Tissue culture on a cutting is an option that can eliminate the unwanted fungi and save the genetics. Using those genetics to regrow a mother will start fresh and avoid the intrinsic mold that was plaguing the strain prior.

Growing knowledge

The practice of checking mother plants for Endophytic mold is not yet commonplace in cannabis, but the hemp business is leading the way.

They’re testing to create very clean plants, so you don’t have issues during cultivation.

Major growers in the U.S. could save millions in lost harvests with mold mitigation. If your current IPM program isn’t doing the trick, you may want to follow in hemp’s footsteps and look inside the plant.

5 Factors to Keep in Mind When Entering the Regulated Market

By David Perkins
No Comments

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
1 Comment

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.

Seven Steps To Avoid the Green Rush Blues: Investigate Water Supplies Before Planting Cannabis

By Amy M. Steinfeld
2 Comments

A clean, reliable water supply lies at the heart of every successful cannabis farm. It’s no surprise that the stakes for finding land with ideal growing conditions, including adequate water, are high. But new buyers (and lessees) caught up in the green rush often gloss over water rights or are unaware of California’s byzantine rules governing the irrigation of cannabis.

Water rights are complex. Water regulations applicable to cannabis cultivation are even more complex. And our new climate reality convolutes things further. Longer droughts, more volatile weather, political uncertainties, increased groundwater regulation and water quality concerns are exacerbating tensions over local and statewide water supplies. In many areas of California, landowners can no longer rely on local water districts to meet their needs.

A robust investigation of the property must consider water supplies. Because a property’s water supply is dependent on water rights, local ordinances, state regulations, politics and hydrology, it’s important to consult a water lawyer (and in some instances a hydrologist) before closing. A bit of foresight can prevent a grower from being left high and dry.

The following checklist provides a roadmap to conduct water rights’ due diligence. While many of these details are California-specific, this type of due diligence applies throughout the West.

Step 1: Identify Available Water Supplies and Consider Potential Limitations On Irrigation, Including Potential Future Changes

Conduct a site visit to identify existing water infrastructure, natural water features and existing or potential water service options. Next, determine if the property is served by a public water supplier. If that’s the case, the California State Water Resources Control Board (“State Water Board”) does not require any specific documentation to irrigate cannabis, but the water supply must be disclosed in the CalCannabis license application.

Groundwater is generally the best supply for cannabis, but the era of unregulated groundwater pumping is over. Many groundwater basins in California are now governed by the Sustainable Groundwater Management Act (“SGMA”), which requires water agencies to halt overdraft and restore balanced levels of groundwater pumping from certain basins. As a result, SGMA may result in future pumping cutbacks or pumping assessments. It’s imperative to identify the local groundwater basin via the Department of Water Resources’ Bulletin 118, and determine whether the groundwater basin is adjudicated or governed by a groundwater sustainability agency. Growers should also test the local water supply’s pH and salt levels because cannabis plants are finicky and water treatment can be cost prohibitive. If a new well is needed, growers should consult with their local county before drilling a new well. In some areas, moratoriums and restrictions on drilling new wells are on the rise.

As a rule of thumb, cannabis cultivators should avoid using surface water to irrigate cannabis. Surface diversions are subject to the California Department of Fish and Wildlife’s permitting authority. And under the interim State Water Board Cannabis Policy, commercial cannabis cultivators cannot divert anysurface water during the dry season (April 1 through Oct. 31), even if they have a riparian right that can be used to irrigate other crops. During the dry season, cultivators may only irrigate using water that has been stored off-stream. And even during the wet season, cannabis cultivators must comply with instream flow requirements and check in with the state daily to ensure adequate water supplies are available. Cannabis cultivators are also required to install measuring devices and track surface water diversions daily. And buyer beware, a groundwater well that extracts water from a subterranean stream may be considered a surface-water diversion. So be especially cautious if the well is located close to a creek or river.Develop a water use plan to optimize water efficiency 

Step 2: Identify Water Supplies Used On the Property, Including the Basis of Right, and Quantify Historical Use

Review information on historic and existing water use. This may include past water bills and assessments. If there is a well on the property, the seller or lessor may have metering data, electrical records and crop data that can establish historic groundwater use. Cultivators must submit a well log to CalCannabis as part of the cannabis cultivation application. If surface water is available, the purchaser should review the State Water Board eWRIMs database for water rights permits, licenses, stock pond registrations and certificates, decisions and orders. The purchaser should also identify surface water diversion structures and review annual filings to determine compliance with all terms and conditions of the water right. Lastly, the purchaser should request all documents and contracts pertaining to water rights.

Realistically estimate water demand for irrigation and other on-site purposes.Step 3: Confirm Ownership of Right and Assess Any Limitations On Water Right

Determine whether the right has been abandoned, lost to prescription or forfeited. Evaluate the seniority of the water right, availability of the right, adequacy of place of use, purpose of use (must include irrigation), season of use, and quantity of any permitted or licensed post-1914 right. Determine whether historical diversions pursuant to an appropriative right support the full amount of the claimed right, and whether any changes to the water right are needed to support the proposed new use. Cultivators in California who plan to utilize surface water also need to file for a “Cannabis Small Irrigation Use Registration” to store water during the wet season for use during the dry season.

Step 4: Reconcile Water Demand With Available Supply

Realistically estimate water demand for irrigation and other on-site purposes. Develop a water use plan to optimize water efficiency (drip irrigation, rainwater harvesting, water monitoring, hoop structures) regardless of supply sufficiency. Many counties, such as Santa Barbara County, require that cannabis growers meet certain irrigation efficiency standards. Determine whether available supplies can meet all proposed demands, including plans for full buildout. If not, consider whether additional supplies are available for use on the property.

Step 5: Determine Water Supply Compliance Obligations

 The rights associated with water supplies are defined by their source, the time frame during which supplies can be taken, the quantity of water to which the right attaches, and any limitations on the purpose of use of the water supply. There may also be reporting requirements associated with taking and using the supply—these can include requirements to report the quantity of water used as well as information regarding the end use of the water. Failure to timely report can have serious consequences. Cannabis cultivators are also subject to additional water quality regulations and restrictions, including waste discharge requirements pursuant to the State Water Board’s Cannabis General Order.

Step 6: Negotiate Deal and Draft Conveyance Documents

After obtaining an understanding of the water supply associated with the property, the property conveyance documents may be drafted to incorporate the transfer of rights associated with the property’s water supplies. These may include the assignment of contracts pursuant to which water supplies are obtained, the transfer of permits or licenses as to the water supplies, or the transfer of water rights arising out of a judgment or decree.

Step 7: Consider Unused Water Supply Assets That Could Be Monetized 

To the extent the water supply rights associated with the property exceed the cannabis plants’ water demand, it may be possible to monetize unused or excess water supply assets through transfer of the rights to a third party.

If you have any questions about water rights related to cannabis cultivation it’s always in your best interest to contact an experienced water attorney early on in the process.

photo of outdoor grow operation

How to Reduce Mold & Contaminants in Indoor, Greenhouse and Outdoor Grows

By Ketch DeGabrielle
No Comments
photo of outdoor grow operation

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.

Outdoor

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.

Outdoor growing has obvious benefits, such as natural sunlight, but may also require extra steps to prevent contamination

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.

Greenhouse

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.

A greenhouse grow facility

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.

Indoor

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.

Talltrees
An indoor cannabis operation set up (Image: Tall Trees LED Company)

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.

Learn more about reducing mold and contaminants in an indoor or greenhouse grow in another article from our series: 10 Ways to Reduce Mold in Your Grow.