how to grow cannabis inside

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.

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.

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.

Before you get started.

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.

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.

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.

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.”

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.

Planting.

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.”

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.

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.

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.

Upkeep.

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.

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.

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.

Always make a list of the power requirements for each piece of equipment and make sure your electrical panels can support the electrical load before you make any big equipment purchases.

Feeding your plant is the process of giving it the chemicals and compounds that it needs to grow out its leaves, roots, and ultimately produce the heavy, trichome-covered flower clusters called colas. There are two main types of feeding systems: drain-to-waste and recirculating.

Grow tents also make it easier for home growers to maintain two separate environments: one for vegetative growth, and the other for flowering. This allows you to keep a perpetual harvest going by propagating and growing young plants in one tent and flowering another set of plants in the other tent. Maintaining a balanced rotation like this can result in maximized harvests year over year.

Indoor cannabis cultivation is a rewarding endeavor that basically can be done in any climate. Growing pot takes attention to detail and the right equipment, time, and money, but the benefits reaped from growing your own weed are more than worth the time and expense. Not only is the practice of gardening itself therapeutic, it also lends a connection to the plants that cannot be experienced outside of a hands-on approach. Having trained and grown out a favorite cultivar to fruition is one of life’s great joys for a marijuana enthusiast.

As a cannabis plant develops, its nutrient needs change. That’s why different nutrient lines are available for different growth phases. Most nutrient lines come with recommended feeding charts. If you’re just starting out, be sure to get to know your nutrients and their ratios.

Odor control.

Hydroponics is a blanket term for the growing of plants in a nutrient solution, with or without an inert medium to provide physical root support. Media such as fused basalt rock and chalk (known as rockwool), coconut fiber (coco coir), and clay pellets (hydroton) can drastically improve nutrient delivery. With a plant’s roots system exposed, hydroponically grown cannabis can grow faster and more efficiently, requiring less water and fewer nutrients but also requiring monitoring systems to ensure a stable pH.

The two main options for an indoor garden are soil and hydroponic media. Consider the following:

If you’re a beginner, prefabricated grow tents are a great option, as they allow for minimal wear and tear on your property. Instead of renovating or building a new room, grow tents can be set up and taken down in a matter of minutes while also providing a clean, reflective, and enclosed environment for your plants to grow. As a general rule, your ceiling height should be at least a height of 8 feet, or about 2.4 meters; this is the typical height of a tent. Check your prospective tent’s measurements before committing to the purchase.

A recirculating system collects the nutrients and water that are used, replenishes them, but with a smaller amount of fresh nutrients, then reapplies the solution to the plants the next time the plant is fed. A grower will check the solution’s pH before and after adjusting the nutrients.

Indoor cultivation provides many benefits compared to outdoor cultivation, including control, reproducibility, and risk mitigation — not to mention location, location, location. The goal is to artificially create the ideal environment for your plants at all growth stages. This is achieved through precise lighting, temperature, humidity, carbon dioxide content, and air movement within each indoor growing space.

When it comes to cultivating cannabis indoors, you need to be sure to provide your plant with the optimal temperature, humidity, air circulation, CO2, and nutrients.

Ebb and flow systems, also known as flood and drain systems, are a popular type of recirculating system that uses a pump to bring water and nutrients from a reservoir into a flood tray where the plants are positioned in their grow medium. The nutrient solution floods the tray and gets absorbed by the roots and medium before slowly draining back into the reservoir. This process repeats itself on a timer to ensure that plants are properly hydrated.

Planning, designing, and implementing an indoor garden can seem daunting, but having a firm understanding of the basics goes a long way in helping a new indoor grower get started on the path to a healthy and bountiful harvest.

With lighting, AC, and other environmental controls in place, indoor cannabis plants will require large amounts of fertilizer or nutrients throughout their lifespans. Hydroponic systems lack the base nutrients that occur within soil; that leaves it up to you, the grower, to feed their plants with nutrient concentrations — the exact formula of which depends upon plant variety and phase of cultivation. With hydroponics, salt-based nutrients typically come in the form of a concentrated liquid or dry soluble powder that can be mixed with water.

Image lightbox.

Distilled and reverse osmosis water are fairly comparable. It’s the process of distilling that differs from the reverse osmosis process. Distilled water has been boiled to a vapor and cooled back into liquid to filter out contaminants. Reverse osmosis (RO) filters pressure water through a filtration membrane and produce wastewater as a byproduct. They’re generally better than distillers at removing volatile chemicals such as chloramines.

Most local jurisdictions require you mitigate the odor from your plants to avoid disturbing your neighbors. Activated charcoal filters absorb plant odor in your grow area. Adding a charcoal filter to your HVAC system or placing one within your grow space is a great way to drastically reduce the odor. The size of the filter is largely dependent on the size of your grow. Make sure filters are sized and installed correctly. Keep track of the life of the filter, as their effectiveness diminishes over time.

Advanced growers use digital environmental controls to monitor all equipment responsible for maintaining a stable environment (i.e., fans, AC, dehumidifiers, sensors, thermostats, etc.). These environmental controls can be worth the hefty price tag for the peace of mind they provide.

When using soil as your primary medium, drain-to-waste is the only possibility. In soilless hydroponic systems, it is up to the growers’ preferences. Most hydroponic growers will opt to maintain a drain-to-waste system, because it affords them full control over the application of nutrients. Recirculating systems are typically reserved for the most advanced and efficient cultivators.

Deep Water Culture (DWC) is a modular bucket system that suspends the plant’s main stem in a net basket while the roots are completely immersed in a highly oxygenated nutrient solution. An air pump supplies the oxygen to the nutrient solution which circulates through 3-5 gallon, or 11.4-18.9 liter, pots. DWC buckets can be configured to run in a stand-alone drain-to-waste system, or all of the buckets can be connected together to run in a recirculating manner.

CO2 can be supplemented into an indoor garden using compressed gas tanks or generators. Using compressed CO2 tanks is the most common method because they’re readily available, easy to set up, and do not add any extra heat to your room the way a CO2 generator does.

Water.

Before you purchase any equipment, it is important to understand the possible limitations of an indoor garden. Consider the height of the ceiling, how much insulation your space offers, and your ease of access to electricity and water. Some local jurisdictions may also ask that indoor gardens mitigate odors during the flowering phase.

Even when growing cannabis legally, it’s a good idea to minimize your public visibility as a grower and take some mild to moderate precautions. Simple steps, such as not geotagging your location when you post grow pictures or hiding the glare from your grow lights when you run them at night, can go a long way in keeping your prized indoor garden secure.

Fluorescent lights are affordable and use minimal wattage to produce a low-intensity light. They are available in strips or larger arrays of multiple bulbs, and are most commonly used during the germination and propagation of seeds and clones. They should not be used during the flowering phase.

Nutrient Film Technique (NFT) is another recirculating system in which plants are suspended by net baskets or neoprene collars that run along a trough. A thin film of water and nutrients continually circulates through the bottom of the trough, providing food to the tips of the roots, while leaving a majority of the root mass exposed to air.

Water quality is another key aspect of indoor gardening. It’s important to determine water acidity and general mineral content prior to planting. Checking the pH, the acidity or alkalinity of the water, is easy to do with a handheld water quality meter. The same device can be used to check the total mineral or chemical content of your water as well. Knowing these things will help you determine the correct amount of nutrients to feed your plants or if fresh water needs to be introduced.

Cleanliness in an indoor garden cannot be overstated. Clean your entire grow room before your first grow cycle and after every harvest. The walls, floors, trays, irrigation lines, reservoirs, lights, and fans should be cleaned using a three to five percent (3%-5%) hydrogen peroxide solution, an efficient sterilizing agent that leaves no dangerous or toxic residues behind. Be careful what you bring into your grow room. Pets, dirty clothes, and contaminated clones can introduce unwanted pests and diseases.

Hydroponic media are viable indoor alternatives to soil, but they’re considered more advanced because they bring with them a set of challenges that may prove difficult for beginners. Then again, if going hydroponic is in your plans, it’s best to learn the method from the beginning.

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.

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.

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.”

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.”

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.

Trigger the flowering cycle.

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.”

“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.”

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.)

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.

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.”

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].”

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.

Presented by Florida Man DIPA.

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.

Foster the right growing environment.

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.”

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.”

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.”

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.

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.

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.”

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.”

Know the law.

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.

Florida Man is a modern Double IPA with a tropical expression from its blend of American hops, including Citra, Azacca, El Dorado and Mandarina Bavarian. The hops are balanced by delicate peach esters from a unique Double IPA yeast and a dash of Canadian honey malt.