What Happens After Harvest?

While much time, effort and money are spent to create optimal growing conditions to produce the highest-quality cannabis during cultivation, as growers know, what happens after harvest is just as crucial. The drying and curing stages are perhaps the most challenging to get right, as the timing of various processes can depend on flower size and density, and vary by cultivar, too. Preserving terpenes and cannabinoids while also preventing mold and pests requires a delicate balance, and 30% of participants in Cannabis Business Times’ first-ever post-harvest study said they struggle with “maintaining cannabinoid/terpene levels.”

In CBT’s “Special Report: Cannabis Post-Harvest” research, most cultivators indicated they either dry by hanging partial plants (52%) or whole plants (42%). About a quarter of cultivators reported drying flower only on mesh screens or trays (23%), while few reported employing other methods such as processing wet, laying flower and stems on mesh screens or trays, and freeze drying (each 8%).

On average, participants said they dry cannabis for about 10 days. However, their optimal drying times range from more than two weeks (10% of cultivators) down to 4 to 7 days (27%). Of note, 71% said drying is one of the most challenging aspects of the post-harvest process.

Curing also is a challenge for many, according to the data. Nearly three-fourths (73%) of research participants said it is one of the most significant post-harvest challenges. The reason? More than 43% of those respondents cited humidity control.

It’s been said that producing quality cannabis is both an art and a science, and curing is perhaps the greatest example of that, a step that requires a careful balance of both. Cultivation teams need to carefully monitor and burp flower to be sure moisture is retained but that mold and mildew don’t develop. Perhaps because of this art-science mixture, typical cure times vary widely among participants, ranging from more than 30 days (21% of cultivators) down to 4 to 10 days (22%).

A Challenging Endeavor

As mentioned earlier in the report, drying and curing, and specifically targeting humidity for those processes, are among the top three post-harvest challenges, according to study participants. However, 74% of cultivators said hand-trimming is the most difficult step and the top challenge noted. The reasons why participants reported hand trimming is so complicated is because of the availability of skilled labor (35%), efficiency (29%), cost (also 29%), consistency (22%) and quality (12%).

Other than utilities, labor is one of the biggest costs of operating a cultivation facility. When looking at the monthly cost of post-harvest labor alone, 34% of participants reported spending less than $10,000, the most common range selected, while 10% said they spend $50,000 or more, the highest range.

On average, cultivators hire nine employees to run the post-harvest process, according to the research. More than a third (38%) of participants hire two to four people to run their post-harvest operations, while 26% have a team of five to nine people manage drying, curing, trimming and more.

Note: The numbers in charts throughout this report may not add up to 100% due to rounding.

The Right Environment

When plants are alive, ensuring they have the best environment to thrive is key to maximizing growth, quality and yield as well as to mitigate pests and disease. Once cannabis is harvested and moves to the drying and curing phase, the environment still can affect product quality, and maintaining appropriate levels is just as important to preventing disease as it is during cultivation. In CBT’s post-harvest research, participants noted that maintaining ideal environmental conditions, especially humidity, is among top challenges.

When asked about overall post-harvest challenges, humidity control is one of the areas participants struggle with most: 47% reported humidity control challenges in drying and 43% in curing.

Focusing specifically on environmental control challenges in post-harvest, cultivators listed humidity control as the greatest challenge, as nearly half (49%) selected this factor as the one they grapple with most. The next most reported challenge with post-harvest environmental control was filtered fresh air intake (10%). According to CBT’s research, cultivators do not have as much difficulty with targeting temperature as they do humidity, as only 9% said temperature control is their greatest post-harvest environmental control challenge. Notably, 20% responded “none” to this question.

Humidity in Drying

The average humidity level cultivators like to maintain when drying cannabis plants is about 53%. The most common ranges cultivators selected for preferred humidity ranges during drying were 50% to 59% (noted by 37% of research participants) and 60% to 69% (noted by 22%). Fewer participants (15%) reported preferred humidity levels of 40% to 49%, while 11% said they have no optimal humidity level/goal, but instead prefer variable ranges.

Temperature in Drying

The average temperature cultivators like to maintain when drying cannabis plants is about 65 degrees F. There was more consensus among participants when looking at preferred temperature ranges in drying rooms compared with humidity, as nearly half (43%) said they keep the dials to 65 to 69 degrees F in drying rooms, while another 29% indicated they like conditions just a bit cooler, at 60 to 64 degrees F.

Methods of Control

To achieve desired temperature and humidity ranges in drying rooms, most cultivators reported they use dehumidifiers (71%), fans (63%), HVAC systems separate from cultivation (43%) and combined HVAC-dehumidification systems (33%).

Spending on HVAC equipment for post-harvest varied greatly, with 15% spending $50,000 or more and 22% spending less than $10,000. Another 11% said they do not have HVAC equipment for post-harvest, and 17% said they don’t know how much it cost.

Quality

With all the emphasis growers placed on the post-harvest environment throughout the study, it’s not surprising that when asked, “What do you consider the most important aspect of producing quality cannabis flower in post-harvest production,” most participants (59%) selected “all aspects of the environment.” The next most selected answers were “length of curing time” and “a properly cultivated plant,” both noted by 7% of participants.

Facility Size and Post-Harvest Spaces

Harvests and Yields

The number of harvests a cultivation company produces in a year depends on many factors, including if cannabis is grown outside or indoors, the facility size, and whether growers are running perpetual harvest systems. Because of that, it’s no surprise that participants indicated a wide range of figures when asked how many harvests their operations produced in the past 12 months. The vastness of that range, however, may surprise some: At the very top of the spectrum, 11% said they had more than 50 harvests in the past 12 months; the same percentage (11%) said they had one harvest in the past year. (Though we cannot assume these are outdoor growers, note that 12% of study participants operate outdoors only.) A third of participants reported two to five harvests, the most of any range provided.

Do Cultivators Package Their Own Products?

The final step in the post-harvest process is either sending product off to be packaged, distributed and sold, or packaging products in house. As part of the “Special Report: Cannabis Post-Harvest,” CBT explored how many growers are packaging their own products for sale. Most participants (85%) package and/or produce some or all of their own products. The chart below details which products cultivators are producing and which they fulfill with packaging. Other than flower and pre-rolls, “other concentrates (i.e., crystal, rosin, kief)” is the top product category cultivators reported producing, with 30% of research participants indicating they make those in-house.

About the Research Participants

Many participants (43%) said they operate two or more types of cannabis cultivation operations (p. S10). However, more said they operate an indoor facility only (40%) than outdoor only (12%) or greenhouse only (5%). Also, more said they operate retrofitted facilities (45%) than those planned/built to specifications (29%), and 24% said they operate both retrofitted and spec-built. More participants have headquarters and are operating in the West or South than other U.S. regions.

The use of cannabis and CBD is increasing among seniors living in California, according to a report published in the Journal of the American Geriatrics Society. Researchers affiliated with the University of California at San Diego surveyed 568 respondents at a geriatric clinic in southern California. All of the study’s participants were at least 65 years old, and 73% of respondents were older than 75.

Around the world people are coming to grips with the health issues and economic fallout of COVID-19. Public awareness of viral contagions is reaching unprecedented levels, presenting an opportune moment to address disease problems within the cannabis industry. As we are seeing with the novel coronavirus pandemic, harmful viruses emerge and adapt, and this is not exclusive to humans. Cannabis growers are increasingly experiencing the negative economic outcomes of decreased vigor, lower flower yields and reduced production of primary target compounds including both cannabinoids and terpenoids. What we are calling “Cannabis disease syndrome (CDS)” exhibits a suite of consistent symptoms, but with no readily apparent single cause. These symptoms, which do not appear to be caused by nutrient deficiencies or other pathogens, are often collectively referred to as “dudding” or “dudders.” (The term originated when growers would think a plant with decreased vigor or stunted growth was “just a dud.”)

Steadily declining vigor in commercial Cannabis clones is not a new phenomenon. As vegetative reproduction by rooting cuttings became popular in the 1980s, growers would occasionally see a clone that became weaker and less productive each time cuttings were flowered. Apart from lowered yield, there were few other symptoms of infection. We tentatively called this a “photocopy effect” based on our analogy that copying a copy of a copy of a copy, results in a faded image that eventually becomes a mere ghost of the original.

We knew that because lost vigor was appearing in asexually multiplied serial cuttings the problem could not be explained by “genetic drift,” which is a shift in the frequency of genes within a small sexually reproducing population. Growers wondered what the causes might be, and even addressed the possibility that simply making serial cuttings might result in diminished vigor.

Soon we realized the symptoms were caused by transmission of an infectious disease that became more and more prevalent through successive rounds of multiplication. (More on this later.) We destroyed clones exhibiting symptoms, carefully sterilized benches, pots and tools, and began to use fresh blades when taking cuttings from each mother plant. There were no known causes, just obvious adverse effects. Yet we found practical solutions, and soon the problem nearly disappeared.

Some similarities exist between the CDS we are experiencing today and COVID-19. Much like the human coronavirus, CDS is difficult to detect at first, as there is a wide range of symptoms. Through our and other growers’ observations of affected plants during the past few years, we have learned that vegetative plants can transmit CDS, while flowering plants are more likely to suffer the consequences. Because symptoms are not readily visible and are easily confused with other diseases, they both lie hidden within populations, and can very quickly become economically impactful. Another similarity between CDS and COVID-19 is that asymptomatic plants can infect the otherwise healthy, with more serious outcomes for some than others. Molecular testing is required to identify potential infections, and there are few laboratories that can effectively identify the causal organisms. Other than practicing social distancing and establishing quarantines, there are as yet no solutions to stopping their spread.

Cannabis disease syndrome cannot be attributed to a single pathogen, although there is a primary candidate for its cause (more on this later). In symptomatic plants, several infectious organisms may be involved, making accurate diagnosis and effective control even more difficult. If CDS killed more of its hosts rather than simply making them sick, then it would have been noticed much earlier, and should not have already spread so widely. As we also have observed while studying affected plants, the cannabis disease syndrome spreads most quickly by taking cuttings from infected plants, using them as mother plants, and thereby multiplying the disease through future generations.

What causes CDS?

In the Spring of 2019, two laboratories independently identified hop latent viroid (HpLVd) within a number of California sinsemilla clones, and this pathogen is the prime suspect in our search for the causal pathogen of the CDS we experience today. Originally discovered in Cannabis’s closest relative Humulus lupulus, the source of hops cones used in brewing beer, it is unclear how it spread to Cannabis. Unlike viruses and other diseases with more readily apparent symptoms, HpLVd is symptomless in most hop cultivars, affecting only the most susceptible. And, co-infection is often first indicated by the symptoms of opportunistic fungal pathogens that infect hop plants weakened by HpLVd, or plants weakened by HpLVd may become more susceptible to fungal or bacterial diseases, similar to the situation we face in diagnosing its infection of Cannabis.

How can we know if our plants have CDS?

Infected plants vary from the healthy norm. CDS symptoms are subtle and difficult to perceive and are therefore most noticeable in clones with which a grower has intimate familiarity. The foremost outcome of a CDS infection is lowered productivity resulting from a loss of vigor. Plants grow more slowly, flowers are smaller, and resin gland development is slowed. Lower branches appear to grow away from the central stalk more than usual and sag, while the main stem grows erect. Other common symptoms include brittle stems that easily break when bent, distorted leaf growth, variegated and chlorotic leaves and overall stunted growth, resulting in drastically lowered expression of terpenes and cannabinoids.

Although the presence of HpLVd may initially be asymptomatic, as it progresses, additional symptoms begin to appear such as stunted growth, general yellowing of the foliage, discolored mosaic blotches or streaks, interveinal yellowing, deformed leaf margins of younger leaves and discoloration within the stems, all characteristic symptoms of possible opportunistic coinfection by fungal or bacterial pathogens.

Adding more confusion, HpLVd-infected plants may actually exhibit symptoms that can be perceived as favorable, such as darker green foliage and increased branching, which complicates detection and control while increasing its spread through the propagation of seemingly healthy cuttings. Molecular testing by experienced laboratories is the only way to verify the presence of HpLVd.

Viral infections spread internally from infected to clean parts of the same plant, making sampling difficult. Only part of a plant might be infected, maybe just one or a few limbs. Since HpLVd may hide in a minute portion of the vascular system, the only way to know for certain that a plant is healthy is to test tissues from several parts of the plant before destroying it. Sampling each clone for pathogens, and verifying that the cutting remains clean, can be a costly process.

How can we control CDS?

Long before scientists discovered that a human immunodeficiency virus (HIV) is the primary cause of acquired immune deficiency syndrome (or AIDS), health care organizations were already advising people of preventative measures: use condoms, do not reuse needles, sterilize razors, etc. They understood the severity of AIDS and how to curtail its spread long before they knew its cause. As with human viruses, awareness, mitigation and suppression are the key elements in the control of plant pathogens. Once awareness is raised throughout our community, testing must begin to learn the causes of the disease and the extent to which it has spread. Infections must be traced back to their sources, and diseased plants either quarantined or destroyed. If the spread of CDS is stopped, it may eventually die out, or at least reach levels that do not cause widespread economic losses. There are several steps that growers should take to prevent the spread of pathogenic diseases in general, and specifically CDS.

1. Control pests.

Viral vectors include common Cannabis pests such as aphids, whiteflies, thrips and mites that transmit and widely spread viruses and other pathogens by first feeding on an infected plant, and then feeding on an uninfected plant. Effective pest control should be a part of every grower’s strategy.

2. Keep it clean.

Each time you take a cutting, the plant’s vascular system is susceptible to infection. When establishing new mother plants, use fresh, sterile blades directly from the package or use sterilized scissors for every cut to assure you are not transmitting a disease. Viral and fungal infections can also spread via contaminated containers, benches and growing media. Household bleach diluted with five parts water is an inexpensive and effective sterilizer. Spray clean tools, soak scissors, drench containers and wipe down benches. Use sterile media for rooting cuttings and growing flowers. Wash and sterilize your hands or change gloves before moving on to the next mother plant. When possible, buy clean stock from a trusted nursery.

3. Quarantine.

Set up a sterile quarantine area for any new arrivals to your facility, and keep new additions isolated within until you become confident that they are not infected. (Again, the only way to be entirely sure a plant is healthy is testing.) Flower a few cuttings in isolation and watch for disease symptoms before multiplying your mother plants. Better yet, do not accept any foreign plants. As we have observed time and again, most grows become infected by taking in cuttings from others.

4. Limit visits.

An infected plant can touch an uninfected neighbor and spread diseases, and humans who come into contact with infected plants can also spread diseases. Prevent the spread of CDS by keeping people who may have been in contact with potentially infected plants, especially other growers, out of your quarantine and propagation areas.

5. Destroy affected plants.

The easiest, cheapest and most effective strategy is to destroy any mother plants you suspect are infected. Always label and number cuttings so you will know which mother they came from, then later each cutting can be traced back to its source. Should cuttings prove to be infected you should destroy the entire clone—the mother plants and all of their cuttings.

Can I get rid of CDS?

Once CDS is suspected and/or confirmed in a crop there are several possible solutions for its control.

1. Outgrow it.

Viral and fungal infections translocate through the vascular system of the plant and may be left behind in older tissues as plants develop, so it may be possible to simply outgrow the problem. Under vegetative daylength (more than 16 hours of light each day), transplant small mother cuttings into fresh sterile media, feed them well, and grow them rapidly under strong artificial lighting, or better yet, under full natural sunlight. Take small cuttings from the uppermost meristems or growing tips of the fastest growing plants and root them in sterile media or an air rooter with sterile water. The more cuttings a grower roots, the higher the chances of selecting a clean one.

Unfortunately, many of society’s most popular clones, some of which have become industry standards, have the highest chance of being infected. By now they have been through countless vegetative propagation cycles, and each cycle exposed them to possible infection. Whenever feasible, replace potentially infected cuttings with an earlier version of the same clone. Smaller growers who focus on fewer varieties may have started with and still maintain an uninfected clone. Quarantine any new arrival and be sure it performs better before replacing your old favorite.

There are other possible solutions that should be outsourced unless a grower has the resources to try them on their own. Micropropagation of meristems in vitro has been touted as a way to clean an infected clone. Many confuse micropropagation with in vitro culture of callus or undifferentiated cells, the plant version of stem cells. Meristems are the last place pathogens reach as they spread through a plant, and the smaller the cutting, the less chance it will be infected. Micropropagation protocols root tiny meristems in sterile conditions, much smaller cuttings than can be rooted in a typical commercial nursery. Once a clean clone is maintained in sterile culture it remains clean, and when multiplied under sterile conditions its offspring will also be clean.

Micropropagation alone does not remove pathogens. However, nurseries are developing protocols to reduce and possibly eliminate pathogen loads by passing meristems through a series of conditions that kill disease organisms without killing the plant. Although theoretically possible, no company has shown that this process actually works, and results in a disease-free plant that also retains its favorable characteristics. One can only know if cleanup has been effective by first testing to be sure a pathogen such as HpLVd is present before treatment, and then cannot be detected following treatment. A clone that has been “cleaned” should also exhibit the favorable traits it had before it became infected. Before spending money, one must decide whether their clone is worth attempting to recover, or whether it would be more efficient to restart with clean nursery stock or seeds.

2. Sow your seeds.

Unsanitary cuttings are the main root of Cannabis diseases, and rather than trying to clean an infected clone, growers can simply sow seeds. Seed and pollen transmissions of viruses and viroids have been shown for several crops but are unconfirmed in Cannabis. Traditional seed propagation interrupts a pathogen’s life cycle, allowing a fresh start each year. Seeds provide the best chance of procuring clean plants and establishing a new clone. Who knows? You might even discover the next OG Kush!

Conclusion

CDS rarely kills individual plants, which is one reason for its silent spread, but it may well be lethal to our industry. We have no measure of how fast it is spreading. We are only beginning to examine the problem, and as our awareness increases and growers begin to experiment, more effective solutions will certainly appear. As cannabis is increasingly commercialized, disease control will become the responsibility of licensed and certified nurseries that will preserve and distribute clean stock, like all clonally based commercial agriculture from potatoes to berries.

It is high time for our industry to be proactive. CDS as well as other diseases have become part of our industry and are likely here to stay. As with viruses within our human population, we will learn how to live with them and manage them efficiently.

Robert C. Clarke is a freelance writer, photographer, ethnobotanist, plant breeder, textile collector and co-founder of BioAgronomics Group Consultants, specializing in smoothing the transition to a wholly legal and normalized cannabis market. info@bioagronomics.com

Mojave Richmond is the developer of many award-winning varieties such as S.A.G.E., which served as a springboard for creating many notable cultivars. Richmond is a founding member of the international consulting company BioAgronomics Group. info@bioagronomics.com

Ali Bektas is an Istanbul native who received his Ph.D. from University of California, Berkeley where he worked on field-based DNA detection methods for indigenous farmers in Mexico to monitor local corn landraces against transgenic contamination. He was staff scientist at Phylos Bioscience from 2017 to 2019.

Outdoor cultivators face a plethora of challenges that are unique to the sun-grown method. While growers working in controlled environments can customize conditions, outdoor farmers are at the mercy of nature’s whims. Planning ahead and being ever vigilant are keys to a healthy outdoor harvest.

With that in mind, here are five common problems that outdoor cannabis farmers can encounter—from unique pest problems to extreme weather—and tips on how to deal with them.

Common problem #1: Heat waves.

As explained previously in part one of this three-part series, “6 Greenhouse Problems and How To Solve Them,” extreme temperatures from summer heat and nearby wildfires can impact crop health and quality. TIP 1 While outdoor farmers in these geographic regions are limited in what they can do to cool their crop, one potential solution for dealing with high temperatures is using shade cloths—cloth screens used to reduce the amount of light a canopy receives. Different grades of shade cloth block out varying levels of sunshine (e.g., 10% cloth blocks out 10% of sunlight). Growers can make provisions to shade outdoor plants when temperatures reach detrimental levels (more than 110 degrees F), or when ash from forest fires rain down on sticky buds.

Sunshine cloth is usually utilized to minimize sun exposure to plants, but it will also prevent a majority of airborne ash from settling on the plants. TIP 2 When selecting a sun cloth to purchase, growers should ask vendors questions, including (but not limited to): What is the cloth’s UV susceptibility? What is its typical lifespan? How often do customers swap out old cloth for new? What is the cloth’s weight? The last one is important to determine if the cloth too heavy to raise by hand or for the mechanical system a grower plans on using.

TIP 3 If heat continues to be a problem under the sunshine cloth, then growers can set up fans at the end of each “tunnel” to increase airflow in the canopy, therefore removing heat from near the leaf surface.

Common problem #2: Damage from budworm.

Each year before and during harvest, I get calls from outdoor growers inquiring how to get rid of budworm caterpillars (typically tobacco budworms). Budworm-infested buds generally exhibit chewing damage. An infestation starts with a female moth laying an egg on a cannabis plant. The larvae or caterpillars emerge (eclose) from the egg and feed on the developing cannabis buds. The tissue that has been fed upon may die. The caterpillar also may defecate inside the bud, which may cause the bud to mold from the inside out. Most cultivators only know they have a caterpillar infested crop once the bud structure falls apart at harvest.

When I receive calls related to budworms, my answer is always the same: TIP 4 The best time to observe and catch the caterpillars is in the evening. TIP 5 When scouting for budworms, growers should thoroughly inspect the plants and buds, and remove and kill all caterpillars and infected buds.

While Spinosad may be the recommended insecticide to control tobacco budworm, it is not an approved insecticide for cannabis in many jurisdictions. TIP 6 Therefore, growers can apply* Bacillus thuringiensis sub. kurstaki (aka Btk) before plants are in bud. Btk is a naturally occurring bacterium that is safe to humans and pets. Btk is a stomach poison, so the tobacco budworm caterpillars must ingest the material (active ingredient) to be negatively affected. TIP 7 In addition, the timing of applying Btk is important, as the insecticide is more effective on young or small caterpillars than mature or larger caterpillars. (*Growers should always check that the product being applied is approved for cannabis use by state regulators.)

Dr. Raymond Cloyd, professor of entomology and extension specialist at Kansas State University, notes that Btk may not be effective in managing populations of tobacco budworms later on in the growing season when buds are present because the caterpillars may not ingest enough of the active ingredient to be controlled.

Common problem #3: Poor growth.

A balanced nitrogen, phosphorus and potassium (NPK) nutrient program and pH conducive to healthy growth are needed for quality cannabis, and that’s whether it is grown in a container fed with fertilizer salts, or in field soil that has been amended. It is best that growers know both the NPK and pH of the growing medium prior to introducing plants to maximize growth and health. TIP 8 Whenever possible, growers should take soil samples to a lab to get an unbiased, accurate measurement on both the composition and the pH of the soil. Knowing the composition and pH of the soil will help to determine what amendments to add to a depleted soil.

Organic grape farmers often use waste byproduct from the crushing process to make compost that feeds the soil in which the next grape crop is grown. Other farmers use alfalfa as a cover crop to till back into the soil to increase the soil’s nitrogen content. TIP 9 While many jurisdictions’ cannabis waste laws won’t allow cannabis farmers to use cannabis waste in a compost mix, cover crops can be a good soil remediation tool for many outdoor farmers.

TIP 10 For information on what NPK and pH levels to target, refer to the Nutrient Matters series from researchers at North Carolina State University in Cannabis Business Times. (“New Research Results: Optimal pH for Cannabis,” “Balancing the Nutrient Equation in Cannabis Cultivation”)

Common problem #4: Early winter storms.

As the climate changes and becomes more volatile, growers must learn to expect the unexpected, such as some geographic locations having fierce hailstorms or unseasonably early snowstorms.

Last growing season, I saw social media posts in which outdoor farmers dealt with both situations: plants beaten down and destroyed by hailstorms, as well as snow-covered plants a few days before harvest. In Canada, I saw a video of a grower harvesting outdoor plants in an October sleet storm that was earlier than any previous storm on record.

TIP 11 With that in mind, outdoor growers in areas prone to extreme winter conditions may want to proactively design and construct frames that allow them to easily cover plants in the event of unseasonably cold weather and/or extreme weather conditions.

While this is not a solution for cannabis farmers, Napa Valley vineyards have 20-foot wind machines/air movers in them; these are essentially 20-foot-tall round poles with two propellers attached to motors on top. Among the grape vines are smudge pots (also known as orchard heaters), oil-burning devices used to prevent fruit trees from freezing. These smudge pots can be filled with diesel fuel and set ablaze to keep crops warm. The smudge pots create heat, and the propellers move the warm air throughout the vineyard. While tempting to try, the smoke from the burning fuel could contaminate cannabis crops.

Temperatures are not likely to get so low for so long before a cannabis harvest that it would require the use of heaters, but weather patterns can be problematic. TIP 12 Cannabis growers can use quick-rising hoop houses to protect their crops from snow and/or ice storms. Covering crops is a time-tested solution used in other large-scale produce industries, including blueberry farms.

Common problem #5: Watering.

As mentioned in the previous greenhouse article, growers must prioritize the maintenance and upkeep of the watering and fertigation system. TIP 13 In outdoor grows, winter and spring are early opportunities to fix, address or upgrade watering and fertigation systems. Clogged drippers, broken lines, major leaks, etc., are all problematic and are best addressed when no plants are at risk. TIP 14 Growers can use a one-part hydrogen peroxide, 10-part water solution to clean drippers and feed lines.

As global warming continues to be a growing problem, outdoor farmers, more than ever, need to expect the unexpected and the never-thought-of. Being able to quickly problem-solve and adapt to constantly evolving climate changes can be the difference between a year’s worth of work being lost or harvested.

Kenneth Morrow is an author, consultant and owner of Trichome Technologies. Facebook: TrichomeTechnologies Instagram: Trichome Technologies k.trichometechnologies@gmail.com