In Lane Language:

Chemicals, bugs, and growing opportunities

Welcome to Inside the Jar’s inaugural grow advice column.

This column will feature two authors, Sarah and Travis Lane, answering questions about cannabis cultivation. Topics will span the spectrum of home growing, commercial scale operations, biological plant functions, or any number of overlapping subjects.

The two authors are a married couple who have been cultivating cannabis together for years. They are currently converting their expertise to the legal space, establishing micro-cultivation and nursery businesses on the south of Vancouver Island. Sarah is a PhD student in Plant Biology at the University of Victoria, and Travis is a long-time grower and advocate.

Our hope is to provide concise and useful answers to our readers’ questions while encouraging people to grow some plants!

This first round of questions came to us directly, but we will be taking reader questions on social media and email in the future.

I live in an apartment and I’d like to grow my own cannabis. I’m worried I can’t fit four plants in my house. What’s the best way for me to grow on a small scale, even if it means I can only grow two or three plants instead?

SL: Cannabis plants (except Cannabis ruderalis) are reliant on photoperiod to flower, and growers rely on this to manage crop cycling and plant size. There are two phases of growth: vegetative and flowering. Vegetative growth occurs when these plants are exposed to long days and short nights (most folks go for at least 18 hours of light), and flowering growth occurs when they are exposed to short days and long nights (at least 12 hours of dark).

The best way to control plant size indoors is to properly time the increase in darkness that triggers the flowering stage.

Once they begin flowering, it is a countdown to the end (these plants are annuals), with many traditional cultivars harvest-ready in roughly 8-10 weeks after the flowering period is triggered. Cannabis plants also grow differently during this time, elongating stem length for a short period in early flower (referred to as the “stretch”), followed by focused bud development.

For the home grower, this is good news. Get to know the cultivar you are growing, and figure out how much it stretches in early flower. This stretch should be similar every time, so you can customize your own flowering cycle to best fit your growing space. Too tall? Flower earlier. Do you have more room? Give them a couple of extra weeks in vegetative growth.

So how early can you start flowering? You can start them on a 12-hour light/12-hour dark cycle right away, but I personally like to give them a little time. For me, I leave plants for a couple of weeks after clones develop roots, or after the first true leaves (the ones that actually look like cannabis leaves) of a seed are showing, as the little baby plants will be busy building roots and the infrastructure necessary to yield healthy bud. If you leave the plants in a vegetative state for a long time, you can also grow giant trees.

TL: Without knowing all the layout details of your home it is tough to offer the “best” solution, but there are a few things to consider.

Plants can vary widely in size. You can grow four smaller plants or a couple of bigger plants and get similar results as far as yield. There are also canopy control techniques that allow the grower to manipulate the shape and size of their plants. Bending branches, known as low-stress training, or “topping” by cutting off the highest branches (aka apical meristems) will change the way the plants grow and develop.

There are several tools available for small-scale home growers who want to segregate the grow space from the rest of the house, too. The main recommendation I would have is to get a grow tent that will fit the space you have designated for cultivation. These are light metal frames that are covered in canvas that can be zipped up to be light-tight, which helps you control light exposure. There are holes to connect ducting for climate control and cables for other hardware.

Space-wise, this keeps the grow tightly contained, which also helps you manage climate and airflow.

Whatever you do, I would avoid the all-in-one solutions like Grobo, Stealth Box, SuperCloset, and BC Northern Lights grow boxes. In my experience they are overpriced and less effective than cheaper solutions.

Grow tents can simplify home cultivation (Wikimedia Commons/Plantlady223)

I’ve been a fairly successful black market grower for five years and I’m considering getting into the legal industry. Should I work for a big company or start my own gig?

TL: Full disclosure, I am very biased on this topic. I have stayed independent despite offers from large companies, and I fully expect to see a financial windfall as a result.

My reasoning isn’t just financial, though, as I have a vision of bringing my version of the old culture into the legal market. I want to run a small team in a small facility, producing high quality product that is distributed regionally. I see this as a lifelong career that never would have been viable under prohibition.

I think the answer to your question depends on what you want and your threshold for risk. Staying independent provides no security until you have significant success, but offers a much higher upside. A corporate position, on the other hand, offers a secure income and the ability to leave your work behind when you go home, but you are unlikely to get rich or find a creative outlet.

My black market experience led me to be accepting of risk. Having spent so much time with the spectre of law enforcement hanging over me, some financial uncertainty and business risk doesn’t impact me like it might a recent college grad with a big student loan debt.

If you want to build something that is yours, and you have a love of cannabis and gardening, I would lean towards building something of your own. The downside is in order to be successful at this endeavour it is important that you treat it like a start-up business no matter your experience. You will be doing work at midnight. You will be stressed. Nothing will be certain.

You will also need to consider a bunch of non-cannabis business stuff. Some level of dealing with human resources, managing expenses, ordering supplies, branding, bringing goods to market, and interacting with the regulator will all fall on your shoulders.

If you decide to take a position with a bigger corporation, it is important to go in without preconceived ideas of how to do things. Their methods are established, and they want people that are willing to learn. You will be one cog in a bigger machine, with clearly defined responsibilities. You will go to work, execute, then be free from these responsibilities.

One caveat for today’s market is that many of the larger companies are facing financial troubles. If you do end up looking for a job in this market, do some due diligence to make sure that the company is on solid ground before taking the job.

SL: I suppose I am also biased, but maybe less than Travis is. I am definitely not as likely to take risks. I think that the primary advantage of doing your own thing is the freedom to do whatever you want (which sort of goes without saying), but the cost and time needed to be successful is high. I can attest to burning the midnight oil, and I can’t remember my last day off.

From my vantage point, I think that there are many benefits to joining a larger company, at least for the first couple of years in this system of legalization. Depending on your background, the regulatory requirements can be daunting, costly, and time consuming, and there is no guarantee that it will all work out. Having enough capital to handle potential delays is really important, too, and not everyone has deep pockets.

These issues will eventually be resolved as the system becomes more efficient, but it's anyone’s guess how long that will take. In the meantime, you can get your feet wet in a space that has already been approved or maybe is in the process, without a ton of risk.

There is also a third option, in which you don’t have to work for a giant company, but you can take employment with a smaller company. This, in my opinion, is a nice intermediate, as there is likely room for you, depending on who you are working with, to be a bit more creative and personal, but still have the support of others. These positions may be harder to find, though.

No matter what you decide, there will always be a need for qualified and talented growers in the space.

I have space for a small four-plant grow in my garage, but it’s a little damp and drafty. How can I prevent mold and airflow issues?

SL: Mold is a dreadful thing. I check my plants constantly for it. The two types of fungal pathogens that are of significant concern to cannabis growers are powdery mildew and Botrytis cinerea. Neither are unique to cannabis. For example, roses are very prone to powdery mildew, and Botrytis (or grey mould, or bud rot, as it is commonly called), is a ridiculous nuisance for many plants ranging from strawberries and hemp to African violets and other houseplants. Of course, even grey mould has its uses: in wine-making, it masquerades as noble rot, and helps make several unique and delicious dessert wines.

Powdery mildew and grey mould are two very different pathogens. Powdery mildew is an obligate biotroph, meaning that it must feed on living plant tissues. It predominantly affects the leaves. If the plant dies, though, the pathogen dies, too, so it doesn’t do a huge amount of actual damage to the host plant. Instead, it can affect yield and growth rates of the plant by redirecting some of the plant’s nutrients to itself. It’s presence is also a warning sign that humidity problems favoring more serious pathogens, such as grey mould, are afoot.

Powdery mildew on a pumpkin leaf (Jeff Kubina)

Grey mould is an opportunistic necrotroph, meaning that it feeds on dead plant tissues. It can and will kill living plant tissues to generate a food supply. It often attacks weakened, aging, or stressed parts of the plant. In Cannabis, it prefers the interior spaces of the buds, causing massive damage as the infection progresses. Unlike powdery mildew, this pathogen survives regardless of how its host is doing, and can cause plant death if kept unchecked. Aside from the obvious plant death consideration, even small infections are a very major problem in Cannabis cultivation for two major reasons: it affects the main part of the plant used for consumption and it is not often visible, buried deep inside the buds.

Where powdery mildew can hamper growth and affect yield, grey mould can cause catastrophic crop failure. Many people don’t even notice until harvest that Botrytis is present, so it is worth being extra vigilant and doing everything possible to prevent its occurrence.

The best prevention is keeping your plants healthy and giving them good airflow. Many growers will remove some of the bigger fan leaves (usually the ones underneath of branching points along the main stems) so that air can get through. Keeping the humidity down is also helpful, especially in the case of grey mould, since low humidity allows for the release of more moisture from the buds.

TL: There are a few tricks I use to keep mold at bay, aside from the obvious. You should already be using mechanical dehumidification to keep humidity down and doing what you can to control temperatures.

Make sure your plants are robust and healthy at all times. This may also sound obvious, but it is an important factor that often impacts new growers. Make sure plants are watered properly, fed properly, and happy. A weakened plant is more likely to be a target for pests and pathogens. One way to boost their pest resistance is to use aloe as a foliar or soil drench. Silicon will also help, as it promotes the reinforcement of cell walls.

The biggest trick is air movement. Your plants should be swaying in the breeze at all times. Put fans in the room to move the air around regardless of how you are bringing fresh air into the space. These can be stand fans or wall-mounted. You can use many small fans, or a few larger oscillating fans. Plants breathe from the bottom of their leaves, and this transpiration releases water vapour. If there is not enough wind, this moisture can build up, creating a mold risk.

Another tip: don’t let your temperatures fluctuate too much. Keep night and day temperatures close together. I set 78F for the daytime and 73F for the nighttime. The reason for this is often referred to as dewpoint. When there is moisture in the air and the temperature falls, this moisture turns into small beads of liquid on the plant’s surface, like dew outside. This moisture is the single biggest vector for mould.

The next consideration is genetics. Some cultivars are prone to certain types of mold or pests, others show resistance to these issues. If you are facing mold issues with a specific plants, it may be worth finding some that are resistant to the issues you face. This is not easy, and it can take time to find suitable options, but once you find them you can grow them forever.

My responses above are focused on a garage with minimal sanitation and biosecurity, but it is definitely worth taking steps to bolster these systems. Having a filter on the air coming in and changing into clean clothes before entering the grow space will both help a great deal with preventing any outbreaks. Sanitizing the space with H2O2 or bleach after each harvest is also a good idea.

Two-spotted spider mites (Wikimedia Commons/CSIRO)

I’d like to use natural pest control with my small grow at home. What are my options, which ones work best, and where can I buy them?

TL: I understand the goal here is to minimize systemic pesticide use, but there are some terminology things I would like to get off my chest. Terms like natural mean very little, as everything is natural. Chemical-free is even worse. Everything, including humans, are made up of chemicals. Even organic has become a marketing term, and many who identify as organic growers are oddly opposed to modern scientific developments.

On large scales, cultivation can be very difficult, and the use of pesticides and herbicides should be evaluated based on evidence, not fear.

Now that I am done with that, I will get to what the question is actually about. I don’t like spraying anything that is highly toxic to humans, particularly in my home, and it is generally unnecessary if proper precautions are taken.

This means using the basics of integrated pest management (IPM), a horticultural term that refers to the constant implementation of pest control and prevention systems. This starts by being proactive, which is particularly important when using biocontrols (such as using beneficial insects) and biodiversity to limit damage from pests.

From the beginning of any cycle, as far back as cloning or bringing in starter plants, pest pressure (the risk of infection) should be considered. Learn the signs of pest damage and what the pests look like, then check every plant regularly. Keep plants well watered and well fed.

Personally, I use aloe and silicon to supplement the plant’s natural resistance, and I also introduce bugs that act as predators for common pests.

SL: I deliver a lot of natural pest controls using soil drenches and foliar sprays, aside from beneficial insects.

A soil drench is essentially what you do every time you water, only here, we are adding a variety of good stuff so that it can interact with the roots. Soil drenches are a good way to deliver that aloe and silicon, but if you are growing in soil you can also use them to promote healthy soil life, which makes it harder for root pests and pathogens to thrive and take over the system. For example, compost teas are a great option for adding beneficial microbes and micronutrients to your soil, and can be customized to favor fungi or bacteria.

A foliar spray is a mist applied to the leaves, and delivers whatever you are spraying directly to aboveground plant parts. This is hugely helpful when dealing with most cannabis pests or pathogens such as powdery mildew, because it is targeted. However, it is important to note that foliar sprays should not be done in daylight hours, as liquid sitting on the leaves can sometimes cause damage if the light is too intense or it is too warm. They should also not be sprayed on flowering plants. Aside from other possible hazards relating to consumption, increasing humidity around the flower is an easy way to end up with bud rot.

Keep in mind that many foliar applications, even those as beneficial and benign as aloe and compost, are not allowed in commercial cultivation under current regulations.

TL: Spider mites, thrips, aphids, whiteflies, russet mites, and fungus gnats are the most common cannabis pests, and all have predators that can be obtained from companies that breed them for the purpose.

For mites I use A. californicus and A. andersoni; for thrips and gnats I use S. scimitus (aka H. miles) and N. cucumeris along with nematodes in the soil; for russet mites I add A. swirskii along with the previously mentioned A. andersoni; and ladybugs work for whiteflies and aphids, which are much more common outdoors.

This is a list of what I apply to commercial crops at outset. At home, I tend to apply less variety, but I always include A. californicus and S. scimitus.

This is not a comprehensive list, either, as there are lacewings, wasps, praying mantis, and many others that are used as predators.

Getting these products is not hard, and they are not too expensive at a small scale. I have purchased from BioBest, Koppert, and Natural Insect Control here in Canada. All of these companies have excellent products, and can offer advice on what to use and how to apply.

If you have a situation where you already have pests, this requires a different reaction. Predators should be used as prevention, not treatment. My fallbacks if I happen to see bugs already include a two per cent solution of Dr. Bronner’s soap (usually use the peppermint soap) in water. I also occasionally use diluted H2O2 and essential oils. Pre-mixed essential oils can be acquired online, from excellent resources like Build-A-Soil.

SL: I would like to add a note of caution on natural pesticide mixtures, especially those containing essential oils. It is worth noting that although these are from a natural source, they are highly concentrated, and can still be toxic. For example, clove oil is still commonly used to euthanize fish. Many are also skin irritants, and it is important that they still be respected as a chemical. Make sure to use caution when mixing, and label your bottles appropriately.

Because of this, it is also important to be careful of the concentration you are using on your plants. In this case, more is rarely better. Some oils can be phytotoxic, burning leaves and causing damage.

They are effective, though, and this should make some sense, considering that essential oils are often compounds that plants make for anti-pest, anti-grazing, or anti-pathogen purposes.