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.
Ultimately, the costs of equipment and recurring utility bills are more expensive than in outdoor and greenhouse settings. However, specialized indoor cultivation equipment allows cultivators to achieve multiple harvests per year and a more reproducible product. If you’re detail-oriented and technologically inclined, indoor gardening is a fun and rewarding pastime, or could even be a full-time job.
There are several different types of grow lights that serve different purposes, each with their own sets of pros and cons.
Creating the ideal environment
Soil can be much more forgiving and requires less precision when watering and feeding plants additional nutrients. Photo by: Gina Coleman/Weedmaps
Air conditioning (AC) and humidification systems are used to control the temperature and relative humidity of an indoor grow room. The size of each unit is based on the amount of heat the lights and other equipment produce in relation to the size of the space. In an open grow room, intake and exhaust fans are used to constantly exchange the air within the room to maintain a consistent temperature. In sealed rooms, mini-split AC systems are used because they circulate the air in the room without bringing in fresh air.
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.
How to start growing weed
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.
The amount of CO2 you supplement your garden with depends on how much light your plants are receiving, the growth phase they are in, and their overall size. CO2 should only be used during the “daylight” period, as plants are unable to utilize CO2 at night or in the dark. Sealed grow rooms are ideal when supplementing CO2, as open rooms tend to exhaust the CO2 more quickly than the plants can use it.
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.”
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.
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.”
Plant and maintain the vegetative cycle until the plant is mature.
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.
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].”
Find a healthy clone.
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.”
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.)