how to properly grow cannabis indoors

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.

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.

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.

Before you get started.

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.

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.

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.”

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.

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 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.”

Upkeep.

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.

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.

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.

Planting.

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.

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.

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.

Even in legal states, you may want to conceal your crop from judgmental neighbors and definitely from potential thieves. Growing indoors allows you to grow discreetly behind a locked door.

If your space is too humid, you may need to invest in a dehumidifier—also known as “dehueys.” However, keep in mind that while dehueys will reduce humidity, they typically increase temperature—you may need more fans or an AC when adding a dehumidifier.

Most dehumidifiers and ACs have built-in thermostats, but if they don’t, you’ll want to buy an external one.

High-quality weed.

Your cannabis wants a safe, healthy place for root development. Without healthy roots, your cannabis will never thrive. Roots are in charge of water retention, nutrient absorption, anchoring the plant, and they also facilitate vegetative growth.

What type of container you use will depend on the grow medium, the system, and the size of your plants.

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.

Without proper airflow, a grow space can experience rapid changes in humidity or develop pockets of CO2 depletion, neither of which are good for plant growth. CO2 depletion can lead to nutrient lockout, and areas of high humidity are prone to pest infestation, mold, or mildew.

For growers who have a little extra money to spend and want full control over their indoor garden, environmental controllers will allow you to automate the process. These devices are essential for if you’re away from the garden for a long period of time.

Below is a list of things to consider and equipment you will need to purchase to get started growing marijuana indoors.

Dehumidifiers and ACs.

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.

Fans should be positioned to provide direct, even airflow throughout the garden. This typically involves using multiple fans that work together or fans that have oscillation capabilities.

The flowering stage will always take about eight weeks—some strains take seven, some nine, some even more, it depends on the strain.

These are quickly becoming the standard. Roots in fabric pots grow to the outer edges and attempt to bypass the porous fabric wall but are cut back, allowing new growth to occur. This process, called “air pruning,” results in a denser root composition which promotes healthy growth and development.

Tools to measure temperature and humidity.

When starting with clones or seedlings, you’ll want to check your plants every day because they’re delicate and sensitive to environmental conditions. You may need to adjust temperature and humidity levels in your indoor grow space at first to hit the sweet spot for your plants.

Check out our buying guide on indoor lights for more info.

Terra cotta pots offer a unique set of benefits to growers in hot climates.

It’s also a good idea to have oscillating fans to provide a constant breeze in your grow room as it will strengthen your plants’ stems, making them stronger and healthier.

Remember, a common mistake newbie growers make is to overwater plants.

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.

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.)

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.

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.”

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.

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].”

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.

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.”

“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.”

Presented by Florida Man DIPA.

Know the law.

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.

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.

Sticking to that schedule is key, he added. “Say you’re at day 30 of the flowering cycle and you come into that closet when it’s supposed to be dark and turn a bunch of lights on. You’re going to throw the whole cycle off and that’s the end of that. It only takes 10 seconds.”

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.”

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.

Trigger the flowering cycle.

Though the 12-hour interval is fairly universal, knowing exactly when to induce flowering is less clear. For the home grower, it usually comes down to space; the longer one waits to trigger the flowering cycle, the taller their plant will be. A good rule of thumb: cannabis will only continue to grow 30 to 50 percent once the light source is reduced. If the plant is growing in a closet, growers should trigger the flowering cycle, understanding that there must be more than two feet of space between the canopy of the plant throughout the entirety of its life.

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.

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.

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.”

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.”

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.”