So it grows

Esteban Lopez/UnSplash

By Kimberly Kirchner, Herbalist Staff

With at-home growing legal in Massachusetts, marijuana aficionados and hobby horticulturists alike are trying their hand at cannabis cultivation. Marijuana plants are a bit more complicated than the average houseplant, however, and the combination of high startup costs and complex care requirements come as a shock to many would-be growers. “It requires a lot of attention to detail,” said Tim Mack, owner of Berkshire Hydroponics in Pittsfield, “and it’s a lot of work.”

Still, growing your own cannabis has its upsides. As Max Lowenstein, who co-owns Berkshire Glass & Grow in Great Barrington with his brother, Daniel, pointed out, an expensive grow setup can easily pay for itself in money saved on buying product from a dispensary. And while raising plants from seed to harvest requires an understanding of everything from biology and agricultural chemistry to the basics of the lighting spectrum, there are plenty of experts willing to share their experience.

The most common thing people look for at Berkshire Glass & Grow, Max Lowenstein said, isn’t light bulbs or fertilizer — it’s information. With the outdoor growing season winding down, for example, “we have people in every day now asking for advice on their harvest,” he said.

Below is a basic overview of the growing process, covering what decisions you’ll need to make, when you’ll need to make them and how to know you’re on the right track.

Growing outdoors

Outdoor cultivation is the least time- and resource-intensive method for cannabis growing, as it leaves much of the work to nature. Sunlight and the open air replace expensive lighting rigs and ventilation systems, while the natural changes in daylight throughout the season will trigger flowering without need for human intervention.

At the same time, outdoor grows are much harder to control than an indoor setup. It should shock absolutely no one to know that sometimes the weather in New England is unpredictable. Cannabis is a fairly hardy plant that can tolerate a broad range of temperatures, but sudden cold snaps or heat spikes can seriously damage or even kill a crop. Outdoor plants are vulnerable to the same mold and mildew that can plague indoor crops, but face added danger from wild animals and roaming pets.

Growing outdoors isn’t an option for everyone. By Massachusetts law, adults can grow their own plants but they must not be visible to the public, and they must be secured by a lock or other security device. For most people, this involves building something more substantial than a chicken-wire fence around the garden. Depending on the size or your grow, a decent privacy fence and locking gate can cost hundreds of dollars. Unfortunately, cannabis plants have a higher theft risk than your typical garden plant, so additional security measures like surveillance cameras and motion-detecting lights may also be necessary.

Before choosing an outdoor grow setup, you should also make sure your soil is cannabis-compatible. While fertilizers and other additives can artificially improve conditions, starting with a rich, well-draining soil will make for less work and lower costs in the long run. The University of Massachusetts Amherst offers comprehensive, low-cost soil analysis, which will identify any deficiencies in your soil. The Berkshires are blessed with generally good soil quality, as evidenced by the active agricultural scene, but if you do find yourself on a particularly inhospitable patch of ground, it may be more cost-effective to use pots and store-bought soil.

Indoor options

Thanks to a long history of prohibition, growing indoors has become the default method for cannabis cultivation. Raising plants inside involves higher operating costs and more hands-on time with the crop, but it also allows for more control over the final product. For this reason, it remains the most popular option for hobby cultivators.

The primary challenge for indoor growers is recreating an ideal environment in a closed space. This involves maintaining the right heat, humidity, soil quality, water levels and lighting scheduling, with the help of careful monitoring and a substantial arsenal of equipment. There are also the issues of space and smell, which, while manageable, should be addressed with any cohabitants before turning the basement into a cannabis farm.

There’s also a third option, which is slowly becoming more popular now that growers don’t have to worry about hiding their operation: greenhouses. A long-time staple in the wider gardening world, greenhouses offer a best-ofboth-worlds solution. They allow sunlight in, decreasing dependence on heaters and supplemental lighting, while keeping rain, wind and inconsiderate herbivores out. Retractable roof coverings are available for growers who want more control over light schedules, and frosted or textured paneling provides some additional privacy.

Of course, all those features come at a price. There may also be building permits involved, depending on greenhouse size and your local regulations. For a first time grower, it’s probably overkill, but if you’re a serious hobbyist or grow other plants, it may be worth the investment.

Lighting up

Indoor cannabis plants have expensive tastes, as far as plants go. The up-front cost of a hobby-size setup can be alarming, but it’s important to remember that spending the money on quality equipment early on can pay off later as reduced electric costs and increased yields.

Lights are often the most expensive part of a grow setup, and arguably the most important. Plants require a full spectrum of light to grow well. While the typical household lightbulb is designed with visible brightness in mind, grow lights give off the specific wavelengths — some of which humans can see, and some we can’t — that cannabis plants need to convert into energy and fuel new cell growth. Plants are also sensitive to changes in the mix of wavelengths they’re exposed to, interpreting shifts toward the infrared end of the spectrum as a sign to move on to the next growth stage.

High intensity discharge (HID) bulbs have long been the industry standard thanks to their intense light output and relative affordability. There are two main subsets of HIDs: metal halide (MH) bulbs, which produce a more summer-like blue-white light used during the vegetative state, and high pressure sodium (HPS) bulbs, which mimic autumn light with a warmer orange tone that triggers flowering. A comprehensive grow kit should have both, as well as high-quality ballasts to run them in.

The biggest drawback to HID bulbs is the massive amount of heat they produce. You’ll need a way to dissipate the extra warmth, such as air-cooled reflector fans, as well as a secure mounting system that will keep the bulbs a safe distance away from your heat-sensitive plants. Depending on the size and configuration of your setup, you may need to install ducting and exhaust fans to prevent overheating, substantially increasing your initial costs.

LEDs have been common in consumer products for decades now, but have only recently gained traction in the marijuana industry. As technology improves and prices drop, however, LEDs are on track to become the industry standard.

Unlike HID bulbs, LEDs don’t get excessively hot. This eliminates the need for extra cooling equipment, and also saves on electricity costs, since less of the energy going into the bulb is being spent in the form of unwanted heat. LED bulbs can also be calibrated to emit very specific ranges of light, amplifying the wavelengths plants need to grow but not wasting energy to produce wavelengths that don’t affect yield. A single fixture can easily transition from blue vegetative light to orange flowering light with the twist of a dial, so only one bulb is needed.

Taken all together, the savings on electricity quickly balance out the higher up-front cost of LEDs. With legalization propelling a new wave of innovation in the grow tech market, they’re only going to get less expensive and more efficient as time goes on. “Chip on board,” or COB, lights, for example, are a new form of LED that pack a larger number of diodes into a smaller area for a more intense light output.

Climate control

When cultivating indoors, managing temperature and humidity can be difficult. Most strains of cannabis prefer a max temperature of 85 degrees F when the lights are on, and 70 during dark hours. The size of your space and type of lights you use will determine your cooling needs. If you’re working in an otherwise cool, dry room with low-temperature LEDs, a simple exhaust fan may be enough to keep temperatures correct. If you’re confined to a small space and using HIDs, however, you may need additional fans or even an air conditioner. Cold is a much smaller concern for the majority of home growers, but if you’re using an outbuilding or uninsulated space you may need a heater to keep temperatures in the 60s when the lights are off. Ideally, you should run your lights for a full cycle without plants present to get an idea of their operating temperatures, so you can choose the appropriate climate control measures.

Air flow is also important for keeping humidity under control. Too much moisture can cause mold and mildew, which are health hazards for plants and humans alike. A good ventilation system will bring fresh, filtered air into the room and move stale air out, providing plenty of carbon dioxide for the plants and preventing moisture build up. Constant air flow also discourages smaller winged pests like flies while strengthening your plants’ stems. Finally, vents can be outfitted with charcoal filters to mitigate the distinctive smell of a flowering cannabis plant.

To monitor these conditions, you’ll need a reliable thermometer/hygrometer combo. Look for a model that records daily highs and lows so you can watch for sudden changes in the room’s climate without constant monitoring. You’ll also want a thermostat to run your cooling system. This will ensure that your fans kick on when they’re needed and turn off when they’re not, saving your plants from overheating and your energy bill from unnecessary power usage. Finally, save yourself some stress by investing in a timer to turn your lights on and off automatically.

Now is also the time to pick your growing medium. Indoor growers have two choices: soil or hydroponic. Soil growing, as the name suggests, involves containers full of potting medium (un-scientifically known as “dirt”) which may or may not be supplemented with fertilizers and nutrients. In hydroponic, or soilless, setups, the plants’ roots are placed directly in a concentrated nutrient solution. Hydroponic growing has its advantages, especially on a large scale: it allows for precise feeding, and the liquid growing solution can often be recycled. It’s also a more delicate process with a much smaller allowance for error, so most beginners stay with the traditional soil method.

Pick your plant

A plant in the vegetative state exhibits distinctive multi-bladed leaves.

Photo: Roberto Valdivia/UnSplash

Now that the nursery’s set up, it’s time to bring home baby.

Some strains are more forgiving of beginner’s fumbling than others, but there are no hard-and-fast rules for what makes an “easy” plant. Generally, popular strains are going to be hardier — they’re popular for a reason, after all — but not always. Indicas have a slight edge over sativas due to their short, bushy shape, which requires less trimming and training (more on that later) than taller, more tree-like sativa strains. However, given how widely requirements can vary between strains, even within the same family, your best bet will always be seeking out an expert opinion.

Mack said that looking at individual strain characteristics was more important that trying to narrow your search to a particular type of cannabis. “You want something that doesn’t have really complicated nutrient requirements.” His list of recommendations for beginners included Skunk Hero and White Widow, both sturdy hybrids, as well as Durban Poison, a sativa.

Once you’ve picked a strain, you have another important choice to make: seed or clone? Clones can be appealing to a beginner thanks to their guaranteed genetics and the perceived “head start” of an already-growing plant clipping. But Daniel Lowenstein warned that clones may come with their own issues. “You don’t know the full history of it,” he said. “There may be parasites or health issues. With seeds you get a clean start.”

Besides, Max added, “there’s something very natural and fulfilling about growing a plant from beginning to end.”

But where do you get those seeds? The rules are hazy. Since marijuana is still prohibited at the federal level, it’s illegal to transport seeds in or out of the state. International seed banks, many of them based in Europe, may sell cannabis seeds online by describing them as “souvenirs,” but it’s a shaky defense. Max Lowenstein recommends reaching out to other home cultivators in the area. Since gifting seeds is legal, many hobbyists are happy to swap seeds as a way of diversifying genetics and trying new strands. Seeds are also available for purchase at organized cannabis expos and conventions.

The grow cycle

The cannabis life cycle consists of four main stages: germination, seedling, vegetative and flower. To get the best possible yield, you’ll need to carefully guide your plant through each stage, adjusting your light, water and nutrition levels along the way.

Germination can be described as “waking up” the seeds. Through the application of heat, darkness and moisture, often in the form of wet paper towels covered by a plate, seeds are coaxed into opening up and releasing their first root. This usually takes about five to ten days, depending on the strain. Once the root appears, the seed can be planted in a small container and moved to the grow room, where it will be gently watered and observed for about a week, until its first leaves break through the surface. At this point it is considered a seedling.

The seedling stage represents the plant’s toddler phase. Over the course of two or three weeks, the plant will develop its first leaves, starting with small, single-bladed offshoots. As the plant grows, it will produce larger, multi-bladed leaves. Seedlings are delicate and especially vulnerable to mold and disease. They’re also easy to overwater, as their root systems are still small can’t absorb much moisture. The young plants don’t need much supervision, provided they get a consistent 18 hours of bright light each day and their environment is kept clean and dry. Eventually, the plant will start producing leaves with the distinctive fiveto seven-point shape, signaling its transition into the vegetative stage.

The vegetative state is essentially plant puberty. It’s when the majority of growth happens, and when the plant begins to take on its mature form. It’s also when the plants’ sexual characteristics begin to develop, necessitating a quick detour into the basics of cannabis biology.

Cannabis is a naturally dioecious plant, meaning that individuals can have either male or female reproductive organs, but not both. Female cannabis plants produce the resin-heavy buds cultivated for consumption, while male plants do not. When a female plant is exposed to a male, pollen from the male plant may pollinate the female and cause it to produce seeds. If your goal is to produce more cannabis plants, this is ideal. However, if you’re growing for consumption, the presence of seeds can drastically diminish both the quality and quantity of your harvest.

Many seeds on the market are feminized, meaning they have been genetically manipulated to grow only female plants. Even so, there is a chance of an errant male or hermaphroditic plant popping up, so it’s important to check the sex of your plants as early as possible. Pre-flowers usually start to become visible towards the end of the vegetative period, and can be found in the nodes, the armpit-like nooks formed at the base of each branch where it connects to the stalk. Female plants will have tiny, hair-like pre-flowers at the nodes, while males will have plump, round sacs. Pre-flower shapes vary from strain to strain, so you may need to consult with someone familiar with your particular variety. Any male plants should be immediately removed from the grow room to prevent pollination and free up space and resources for bud-producing female plants.

A close up of the nodes on a young female plant reveals the identifying hair-like pre-flowers.

By Photo by Rotbuche/Wikimedia Commons

During the vegetative state, the plant is sturdy enough to undergo training to maximizing growth. Left to its own devices, cannabis will focus its energy on growing upward, resulting in one main stalk with just a few small side branches. This may be a great strategy for thriving in the wild, but it doesn’t create much flower. By coaxing the plant into growing out rather than up, cultivators can produce more branches and therefore more bud.

These techniques can be split into two categories: Low Stress Training (LST) and High Stress Training (HST). Low Stress Training encourages the plant to redirect energy to its existing branches by bending the stalk to one side, so that lower areas of the plant can receive more light. This is usually done by tying down long branches to create a level canopy of leaves with equal access to the sun or lamps.

High Stress Training is essentially a strategic form or pruning in which the plant’s stalk is cut or broken off at the top, causing new growth to branch out to the side rather than continuing straight upward. Plants can be “topped” multiple times to produce more and more sideways growth. In some cases, entire sections of the plant may be removed. HST does carry some risk of damage or infection if not done properly, but it can be tremendously effective in creating a lush, even canopy.

Plants in this stage should get plenty of water and extra nutrition to promote growth. Feeding cannabis plants is as much an art as a science, and an experienced grower will be able to help you achieve the right levels for your particular strain. A typical vegetative state can last anywhere from three weeks to more than three months. Since the move to the flowering stage is triggered by light changes, we can further extend the vegetative state if necessary to ensure plants are suitably healthy and large enough to begin producing buds.

Flowering is the final stage in the cannabis plant’s development, in which female plants develop the heavy, sticky buds that are harvested for consumption. Cannabis relies on the length and quality of sun exposure to know when it’s time for flower production, so we can trigger this growth artificially by switching to a shortened lighting schedule and more orange-colored light. As the female plants get to work, any sneaky males will quickly become apparent. These should be immediately removed to preserve the quality of the buds.

Good flower is heavy, so at this point plants should be given some sort of support structure to prevent breakage. They may also appreciate specially-formulated blooming nutrients to keep them healthy and energized. The flowering stage is long — upwards of two months, depending on the strain — and while plants shouldn’t be hassled too much during this period, it is important to keep watching for signs of mold or parasites. The heavy aroma of blooming cannabis can attract insects and other pests, so vigilance is needed to keep your plants safe.

If you’ve done everything right (or even just most things, honestly) you’ll soon have a hearty, homegrown crop to harvest and enjoy.

A flowering cannabis plant.

Photo: Robert Baker/UnSplash