Unlike outdoor growing, you aren’t tied to the sun and the seasons. You will be providing the entire environment the plants need to grow, including the grow medium—soil, rockwool, etc.—and regulating the amount of water and nutrients they receive, as well as controlling temperature, humidity, and more for them.
It can be tricky getting the right balance of temperature and humidity because they affect each other—turning up your dehumidifier will lower the humidity of your grow space, but it will also increase the temperature of the area. This in turn may require you to turn on an AC unit—everything’s connected!
You can also use a timer for your fans, but a thermostat is better—you can set it to a specific temperature, and the fans will turn on when it’s too hot and turn off when it’s too cold.
Good soil for cannabis relies on a healthy population of mycorrhizae and soil bacteria to facilitate the conversion of organic matter into nutrients that a plant can use. Alternately, you can use a regular soil mix and then supplement your plants with liquid nutrients.
Plants need fresh air to thrive and carbon dioxide (CO2) is essential to the process of photosynthesis. This means you will need a steady stream of air flowing through your grow room, which will allow you to move hot air out of the space and bring cool air in.
HID (high-intensity discharge) lights are the industry standard, widely used for their combination of output, efficiency, and value. They cost a bit more than incandescent or fluorescent fixtures, but produce far more light per unit of electricity used. Conversely, they are not as efficient as LED lighting, but they cost much less.
Check out our buying guide on indoor lights for more info.
You’ll need to ensure that temperatures remain within a comfortable range for your plants, between 70-85°F when lights are on and between 58-70°F when off. Some varieties of cannabis—generally indicas—prefer the colder side of the range, while others—typically sativas—are more tolerant of high temperatures.
The first step in odor control is making sure temperature and humidity are under control in your grow space—high temperature and humidity will perpetuate odors.
Controlling temperature in your indoor grow room or cannabis garden can be achieved by manipulating these factors:
Equip yourself with these cheap and easy-to-use tools to take measurements in your indoor cannabis setup:
For a root system to develop and thrive, they will need the following:
When designing your space, you’ll need to take into account room for your plants, as well as space for lights, fans, ducting, and other equipment. You’ll also need space to work on the plants. Cannabis plants can double in size in the early stages of flowering, so make sure you have adequate head space!
You can let your plants get as big as you want, and can control when they flower and when you harvest, and you can start another batch right away or whenever you want. You can grow any time of year, even straight through winter or summer, and you’ll get consistent crops each time.
Check out our Guide on nutrients for more info.
You can make this yourself by combining worm castings, bat guano, and other components with a good soil and letting it sit for a few weeks, or it can be purchased pre-made from a local nursery or grow shop.
Soil is the most traditional medium for growing marijuana indoors, as well as the most forgiving, making it a good choice for first-time growers. Any high-quality potting soil will work, as long as it doesn’t contain artificial extended release fertilizer—like Miracle Gro—which is unsuitable for growing good cannabis.
Growing weed indoors is great because you can grow it any time of year and you’ll have complete control over the plant and what you put into it. Live in an apartment or a small house? Don’t worry, you can grow weed practically anywhere, even if you don’t have a backyard or a lot of extra space.
Before someone even begins to consider the genetics of their preferred strain, they should first ensure that their apartment is cannabis-friendly. There are five main factors to consider: space, temperature, humidity, the pH of water, and the amount of light.
For some people, cannabis cultivation is a hobby. Others a life-long passion. But it’s unique in its vast demographic appeal. “Everyone I know grows,” Lipton said. “There are people in their 20s doing it. I know people in their 60s. It’s a fun thing for people. You don’t have to be afraid anymore.” Here are Lipton’s tips on growing your first plant.
Both medical and recreational dispensaries now sell female cannabis clones, which retail for about $15. Alternatively, it’s commonplace for home growers to gift clones to their friends. “When you get a clone, someone will likely give it to you in a four-inch pot. You’re skipping that whole step of having to germinate seeds. You’re already 10, 14 days ahead of the game and basically ready to plant.”
Find a healthy clone.
Presented by Florida Man DIPA.
pH of Water: 6.3 to 6.7. “You’ll need a meter that you can stick into your water and tell you the pH,” Lipton said. “You want something between 6.3 to 6.7 pH for watering your plants. That sounds like pretty sophisticated stuff but it’s really not. A lot of times your tap water will be 7.8. You can use what they call pH down. That’s a crucial step.”
Even with a healthy clone, however, cultivating cannabis can be a long and arduous process — especially in tight indoor spaces. “A lot of people think growing is easy, but it’s not,” Lipton said. “You have to be really on it. Not everyone has success, obviously.”
Temperature: 68 to 78 degrees Fahrenheit. “A tool you should always have is a little temperature gauge,” Lipton said. “They call them hygrometers. They’re cheap and tell you both the temperature and the humidity.”
Relative humidity: 30 to 45 percent. “If you live somewhere humid, you’re probably going to want to buy a dehumidifier,” said Lipton. “In Boulder, we sometimes have to add humidity.” At home, that can be done with a reliable humidifier.
To harvest, many growers begin by removing the leaves of the cannabis plant with trim scissors, followed by the buds (using pruners). “We call this bucking,” Lipton said. “Gloves are also extremely important for sanitation reasons as well as to keep your hands from becoming sticky with the resin from the plant.”
Another layer to consider is that cannabis cultivation must happen “out of plain sight.” “You can’t have any odor. If it’s offending people in the neighborhood, then it’s an issue.”
Know the law.
It’s important to remember that cultivating even one cannabis plant for personal consumption is felony on the federal level and punishable by up to five years in prison. Meanwhile, four US states — Alaska, Colorado, Washington D.C. and Oregon — have passed local amendments, allowing citizens who are 21 years old and over to grow a limited number of plants without fear of persecution.
Despite the hurdles, many first-time growers still choose to cultivate cannabis indoors (which is legal in Alaska, Colorado, Washington D.C. and Oregon), and there are steps to maximize a plant’s chances of succeeding. It all starts with a plant’s genetics. “For your typical closet setup, you’re going to want a plant that stays short,” Lipton said. “A lot of time that means an indica. Sativas are really tall and lanky.” (More on the difference between those two families here.)
While most, if not all, medical and recreational farms cultivate cannabis from seeds, guaranteeing that their plants are free from viruses, most home growers, even those with experience, typically begin with clones — essentially trimmed pieces of female cannabis plants that have been rooted in separate pots. “When most people think of cannabis — you know, what you smoke — they’re thinking about the flowers of female plants,” Lipton said. “When you grow from seeds, half of them will be males. If you’re only going to do one or two plants, you don’t want to waste your time with that stuff.” A clone sourced from a dispensary or a knowledgeable friend guarantees that the plant is female and will eventually produce bud pending proper care. “You can get up to four ounces off the right plant — if you know what you’re doing.”
Light: 2,200k. “For a closet set up, I would recommend a 175-watt HPS light,” Lipton said. “Some people try to use fluorescent lighting, but I wouldn’t recommend that. You’re just not going to get a very good outcome. Nowadays, HPS lights can just go right into your home outlet, and you’d just need a timer [to set the intervals]. Position the light directly overhead. They can be pretty powerful, so you’re going to want it at least two feet from the top of the canopy [to prevent the plant from overheating].”
The last step involves curing the bud. “Curing is just as important as the growing process,” Lipton added. “We do a slow cure, which means that it takes anywhere from three to six weeks depending on variety.” Temperature and humidity play a large role during cure and must be maintained to ensure a great final product. “Our actual cure process is somewhat of a secret, so I cannot share the fine details,” Lipton said. “But it’s an art form and extremely crucial to our success.” The reason growers cure bud after harvesting is that it creates a smoother smoke and increases its potency. Detailed recommendations for proper curing can be found online, here and here.
Trigger the flowering cycle.
To understand the flowering cycle, it’s important to remember that cannabis is a plant. And, like most plants, it follows the seasons. To trigger flowering — which will take 55 to 60 days to complete — growers reduce the time plants spend exposed to the light source from 18 hours to 12. “You’re basically telling your plant it’s mid-September,” Lipton said.
Even in our most progressive states, however, the law is far from simple. “In Colorado, it’s now county-specific,” Lipton said. “When the amendment first passed, they said you could grow six plants per person. But now, certain counties and municipalities have come out and said it’s just six per house — there’s no combining plant counts. That means you can have three vegetating and three flowering at any given time.”
After 55 to 60 days, growers begin paying close attention to their plants’ trichomes — the small, bulbous fibers that develop around the flower of the female plant. “Those trichomes will turn from clear to amber,” Lipton said. “They kind of look like red hairs. You know it’s time to harvest when about 10 to 15 percent of the trichomes turn that color.” On average, cannabis plants have a five- to seven-day window of peak harvest time.
“Growing cannabis in tight spaces is not my usual recommendation,” said Stephen Lipton, the cultivation manager at The Farm Recreational Marijuana Dispensary, an award-winning recreational facility in Boulder, Colorado, specializing in what it calls “craft cannabis.” At any given time, Lipton oversees close to 15,000 plants across seven different facilities in Boulder County. “If you have a really tight space and it gets too hot or too humid, you’re going to have big trouble.”
Cannabis plants yield the highest-quality (and quantity) flowers after maturing. This usually takes about a month to happen. “I recommend planting in a five-gallon Home Depot bucket,” Lipton said. “It’s really important to have proper drainage, so you want to drill some holes in the bottom. The biggest mistake people make is that they overwater and suffocate the roots. Cannabis likes to be watered and dried out before it’s watered again.” During the vegetative cycle, the plant should be exposed to a minimum of 18 hours of light. Remember to open the closet door while the lights are on to prevent the space from heading north of 78 degrees Fahrenheit.
Space: 3 x 3 x 5 feet, minimum. “The bigger the space, the better. With all the lights, closets get hot,” Lipton said. That said, closets help growers control light pollution when the plant is in its flowering cycle — one of the main reasons home growers favor them over larger spaces, such as living rooms. “If you have a spare bedroom, or a basement even, you can just use that and close the door,” Lipton said.
Do your homework and read up on the laws in your state. Some states prohibit growing cannabis, while others, like my home state of California, permits anyone over age 21 to grow cannabis, but only up to a certain number of plants. NORML has a pretty in-depth guide to the laws in each state. Colorado, Oregon, Nevada, Vermont, and Maine also allow cultivation, but again, the specifics depend on the state. Definitely clarify what your rights are before you start the glorious path to at-home bud gardening.
Since clones come from plants that have been grown indoors, let yours chill in a shaded area for a week before exposing them to full sun, Johnson says. “The clone hasn’t tasted sun like that, and the transplant itself will be stressful.”
While you can absolutely grow cannabis indoors, outdoor cultivation is much simpler and cheaper, says Ron Johnson, author of How to Grow Organic Cannabis: A Step-by-Step Guide for Growing Marijuana Outdoors , who also runs the website The Cannabis Gardener. “The sun is free,” he tells Mic. “You don’t have to pay hundreds of dollars a month in electrical bills.” An outdoor garden probably won’t allow you to turn over product fast enough, but it’ll suffice if you just want to grow weed for yourself. Plus, it’s gentler on the planet.
Before you get started.
Cannabis cultivation laws vary widely state-by-state. Also, we can’t stress this enough: Growing cannabis is illegal in a lot of places, and the penalties — which include steep fines and prison time — can be much worse than possession, since growing can imply an intent to distribute. Black and brown folx need to be especially scrupulous about heeding these rules, since law enforcement targets us way more than white people for weed-related charges, even if we consume it at similar rates.
Johnson notes that the outdoor grow season lasts from around April to October, meaning if you plant seeds now, they’d still yield flower, but not much. Since it’s late in the season, he suggests buying a large clone, which will have more branches and therefore yield more flower.
If you buy seeds from a seed bank, look for those labeled “feminized” to ensure they give rise to female plants, Johnson says. But if you’re a total newbie, he suggests buying clones, which are cuttings from a “mother” female plant, available at some dispensaries, as well as at nurseries. Not only are they easier to obtain, “they’re easier to grow. You get a clone, and you transplant it to some soil.”
Cannabis plants can be either male or female. Female plants yield the plump flowers, a.k.a., “buds,” that we know and love, brimming with psychoactive compounds like tetrahydrocannabinol (THC, which gets you high), Modern Farmer explains. Male plants yield much smaller flowers, which people typically don’t consume. In other words, if you want to actually indulge in your crop, you’ll want female plants.
When the pandemic hit, many of us turned to quaint pastimes to soothe our existential dread, whether it was baking sourdough, knitting, or doing jigsaw puzzles. If you want to expand your repertoire of distraction methods with an activity that still has that quiet, homey vibe, but with a bit more of an edge, consider growing your own weed.
There are different harvesting methods, but Johnson cuts the whole plant at the base and hangs it upside down with some twine in a dark room at a temperature of around 70 degrees Fahrenheit. Add a fan for airflow — you definitely don’t want the room to be humid, which will cause mold to grow, rendering your crop unusable. It’ll probably take around a week to dry.
To check if your cannabis is ready for trimming, perform a break test on each branch. If it bends so much it nearly breaks, then it’s ready, and if it breaks right away, it might be overly dry, but still totally usable. Trim off the buds and seal them inside a mason jar for curing, opening it periodically over the course of about four weeks to let moisture escape. Johnson outlines a detailed schedule on his website, including instructions on how to look for mold.
Whatever you do, don’t plant your clones in the ground. They’ll run rampant, and “you’ll have pounds of weed in your house,” Johnson says, recalling the trays of weed atop his kitchen table when his crop grew wild. “You don’t need the stress of plants getting out of control, growing over your fence.” If your neighbors can see them, they might complain about them, and having too many plants could get you arrested.
Your cannabis will be ready to harvest at around October. You’ll know they’re ready when the buds “start to get really, really swollen and packed pretty tight,” Johnson says. But it can be hard to tell if you’re a beginner. Many growers say that if you think your plant is ready to harvest, wait two weeks, since many newbies tend to harvest too early. Or, you could share a photo of your crop on a forum and ask more experienced growers to weigh in.
If you use organic soil, all you’ll really need to do is add water, Johnson says — but don’t overdo it. The number one mistake he sees new growers make is watering their plants too often. In general, “watering every day is too much. The rule is, if you pick up your plant, and the pot is heavy, then it has a enough water. If it’s light, it’s dry, then you need to water.” You could also stick your finger knuckle-deep into the soil; if it feels dry, add water.
Don’t go overboard, though, he warns. Start with growing three plants in five-gallon pots. This way, if one dies, you’ll still have two plants, and the pots will limit their growth. A general rule of thumb is that they’ll grow one foot for every gallon of soil. He recommends mixing your own organic soil, which he explains how to do on his website and will save you the headache of adding nutrients or pH testing. “The soil is what we call alive,” he says. “It’s always breaking things down to replenish nutrients that are missing.” But if you can’t mix your own soil, or don’t feel like it, you could buy organic Pro-Mix soil, which Johnson says many outdoor growers use.
That said, when your plants are fully flowering, you might find yourself watering them daily, based on these indicators. When you do water them, keep going until you see water running off the soil, to ensure the water reaches all of the soil in the pot.
Once you’ve cured your cannabis, sprinkle some bud in a bowl, or whatever your preferred method of imbibing might be, and savor your hard-earned crop.