Compact fluorescent and LED bulbs produce enough light for plants to grow and even to flower, but high-pressure sodium (HPS) fixtures provide the most light in the spectrum that plants need during their budding stage. HPS lights can get hot, so you need a well-ventilated room to use them.
1. Turn Up The Lights
As plants grow taller, the bigger leaves on top shade the lower leaves and branches. That can lead to small plants with buds on only the highest tier. By gently bending the top of a plant, you bring light to the lower leaves, increasing the colas (nodes where buds form) and bringing light to lower-level buds.
3. Train Your Plants
Phosphorus is the critical nutrient during the budding stage. Bone meal, a natural plant supplement, is loaded with phosphorus and calcium, which activates key growth-regulating hormones essential for flowering. Weekly doses of bone meal, starting just before budding begins, ensure that your plants have the phosphorus and calcium they need to bud abundantly.
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.
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.
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.”
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.”
Harvest and cure.
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.
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].”
Plant and maintain the vegetative cycle until the plant is mature.
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.
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.)
For example, it takes less time to grow 3′ weed plants than 5′ plants; in the span of a year, you can maybe grow four harvests of 3′ plants, or two harvests of 5′ plants.
Because the amount of light a plant receives is so important, you’ll need to make your indoor grow space light-tight. Light leaks during dark periods will confuse your plants and can cause them to produce male flowers or revert to a different stage.
Odor becomes much more difficult to manage in the final six weeks of a marijuana plant’s life, when trichomes and terpene production ramps up. You can also get odor-absorbing gels, which replace weed smells with other scents. Keep in mind that odor gels don’t eliminate odors, but simply mask them.
Check out our Guide on nutrients for more info.
Daily maintenance checklist for your indoor marijuana grow
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.
For most first-time gardeners, we recommend buying a quality potting soil that will provide your plants with enough nutrients to get them through most of their growth cycle without having to add many amendments or liquid nutrients. This pre-fertilized soil—often referred to as “super-soil”—that can grow cannabis plants from start to finish without any added nutrients if used correctly.
The growth stages of marijuana can be broken down into four primary stages from seed to harvest:
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.
The biggest variability in how long a marijuana plant takes to grow will happen in the vegetative stage—after the seedling phase and before flower.