This article is brought to you by Hawthorne Gardening Company, providing complete, impactful solutions for growers and their goals.
More agriculture professionals than ever are eyeing cannabis as a way to diversify their offerings—especially after 2018 Farm Bill loosened restrictions on hemp. While growing cannabis can be rewarding, it’s a unique crop with a special set of needs. Careful preparation can be the difference between a mediocre grow and a thriving, successful operation.
We spoke with the horticultural experts at Hawthorne Gardening Company about how to build or adapt an indoor grow space to cannabis, and what to watch out for once you get started. Their team sees two big groups of people that are usually interested in diversifying with a cannabis crop: current greenhouse growers and outdoor container growers. After meeting with them and learning about their unique problems, Hawthorne works with the growers to find solutions that help crops succeed.
The following tips are a great starting point for anyone who’s ready to switch their crop to cannabis. When reading them, keep in mind that you will need to comply with state laws and regulations at all times, no matter what.
1. Boost your lighting (and expect a bigger electric bill)
Just because you have a greenhouse that taps into natural daylight, it does not mean you have lighting taken care of. While a proper lighting setup is a must for any crop, cannabis needs more attention than most and has a complex relationship with daylight. Cannabis flower yield and quality are significantly tied to the amount of light the crop receives.
“In almost every case you’re going to have to add or increase the amount of supplemental lighting that you provide in a greenhouse,” says Dustin Forney, lighting designer at Hawthorne. “Depending on the crop you were growing before, the upgrades needed could be substantial. For instance, if you go from growing leafy greens to growing flowering cannabis, your current supplemental lighting might be as little as one-twentieth the amount of light you really need.”
Once you have the necessary light capacity, there’s one more thing to consider. Cannabis is a photoperiodic crop, meaning that keeping the plants vegetative, or initiating and supporting flowering, is dictated by periods of light and dark. Although there are some exceptions, the general rule of thumb is that cannabis will initiate flowering during dark periods, similar to chrysanthemums or poinsettias. Being able to provide this kind of light is necessary to keep plants vegetative, and you’ll want to make sure you have the ability to cut your lights off entirely for flowering.
“You need more light in the wintertime, especially in northern latitudes,” explains technical services director Rick Vetanovetz. “Long days,” he says, “keep a plant vegetative. But then when day length is already long, you need to create short days to initiate flowering for cannabis, so you need blackout cloth to promote it.”
2. Make sure you have the right space—and plenty of it
When you picture an indoor cannabis plant, you might picture a friend’s amateur closet grow operation or small, picturesque plants in little pots. But a mature cannabis plant gets very tall and incredibly bushy. That dense foliage only exacerbates the crop’s vulnerability to foliar diseases like powdery mildew and Grey mold.
What elevates the challenge of providing for proper airflow through the crop is the need to maximize space in a growing operation. Hawthorne believes there are ways of using space efficiently while not crowding your plants.
“Cannabis plants get big to a point where it’s a challenge to get air to flow through the crop, which you really need to do to avoid foliar diseases like Powdery Mildew and Botrytis Grey Mold. And this is despite trimming operations cannabis growers typically employ during the flowering phase of the crop”, says Vetanovetz. “The newest trend is rolling benches, which have actually been around forever. It’s a bench that moves laterally, side to side, which allows you to spec out your room or greenhouse for increased functionality using one active aisle any time.”
“You wind up recuperating about 20 to 30 percent of your growing space by utilizing something like a rolling bench,” he adds.
Rolling rack systems, which can increase vertical space, are also gaining popularity.
“You can get three or even four layers of cultivation moving up vertically,” says Forney. “Maximizing space in these ways is fantastic, but, controlling the relative humidity and ensuring that enough air flows through your crop is essential to avoiding foliar diseases, particularly as you get close to harvest. For those growers who target the premium flower market, Hawthorne thinks this aspect cannot be overstated.
3. Mind the neighbors
Don’t be so focused on getting the right setup inside that you lose sight of what your grow may look like outside: a glaring beacon of light giving off a dank cannabis odor. Even if your neighbors aren’t especially nosy, it can attract a lot of attention.
“If you’re a flower grower, people love the smell,” says Vetanovetz. “But if you’re growing cannabis, there’s a lot of communities that just absolutely won’t tolerate the smell of cannabis.”
The same goes for lighting. Light pollution that might be a minor annoyance coming from a vegetable grower can raise ire when it comes to a cannabis crop. While it might be a double standard, it’s that much more important for cannabis growers to check any local regulations to make sure the whole operation is compliant. Forney notes that some states set a maximum wattage per square foot of lighting. But even absent of local regulations, neighbors can still come after you as a nuisance.
“At the very least,” says Vetanovetz, “you may want to consider a way to blackout or screen your greenhouse in the evenings to avoid issues. If you’re in the middle of nowhere it’s probably not as much of an issue, but when you start encroaching in a populated area, you need to accommodate other people.”
4. Don’t be afraid to ask for help
“Cannabis is still an emerging industry,” says Forney, so it’s only natural to have questions—but many suppliers will sell equipment to growers without any support, or worse, bad advice.
Hawthorne has multiple brands under one roof, including hydroponics, nutrients, lighting, HVAC, and benching, so they’re well-positioned to make sure growers have the best and most streamlined setups.
Vetanovetz points out that it’s in everyone’s best interest that their customers are satisfied with all the work they do, so they don’t charge for additional product support.
“Our primary role is to support our products, and we do that by making sure that our customers are using them in the right way, shape, and form,” he explains. “If things aren’t working right, it leads to a lot of concern and uncertainty for the client, and our group’s goal is to eliminate that.”
Part of the job is offering words of encouragement to growers from the beginning, listening to what their problems are, then following up to make sure things are still running smoothly.”
In the end, it’s all about trust, professionalism, and knowing the right people to help you convert your crop.
“We have earned a large degree of trust with our top clients by providing excellent designs, advice and service,” adds Forney. “We help our clients implement their design and when they see the positive results, our clients become friends for life.”