Humidity is the amount of water vapor in the air. Here are some ways to control it in your marijuana grow room:
There are many different media to choose from, including good ol’ fashioned pots full of soil, rockwool cubes, a hydroponic tray, and more.
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.
Soil and other media for growing weed indoors
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!
Check out our buying guide on indoor lights for more info.
As your indoor weed plants grow, they’ll need less attention, but you’ll still need to check up on them every 2-3 days.
These are just some examples of amendments commonly used in different types of soils. Heavily amended soils will have long lists that break down all organic nutrients they contain. Some companies create soils that offer a great structure with base nutrients, but allow you to fill in the gaps as you desire.
To maximize the amount of daily sunlight your plant receives, work with the seasons. The total number of daylight hours vary depending on where you are, but in the Northern Hemisphere a good rule of thumb is to germinate your seeds around the Spring Equinox.
Flush your plant before harvesting. If you’ve been feeding your plant with synthetic nutrients or fertilizers, you’ll need to give it a good flush before harvesting. By flushing the growing medium of nutrients and fertilizers, you’ll leave the plant to use up its reserves before harvesting. It’s an important step that, if skipped, can negatively impact the final quality of your flower. Timing is important here because you don’t want to strip your plant of nutrients too early. One to two weeks before harvest is a good rule of thumb.
Make sure your cannabis plant gets enough light
Be a good plant parent. Keep an eye on its growth and development. Trim yellowing or dying leaves that often present at the bottom of the plant when they get shaded by the top canopy. Keep an eye out for insects and act quickly when you see them, then continue monitoring closely because pests and disease can be persistent and difficult to get rid of.
Successfully growing a cannabis plant indoors is all about covering the plant’s basic needs: air, light, temperature, water, and nutrients. So, if you get those things right, your homegrown cannabis plant could provide much more than a fun experiment. And considering that indoor cannabis plants can grow a few feet tall and equally wide, you should anticipate young plants to take up more space by the time they reach maturity.
But can you simply stick a cannabis plant in a nice sunny window and let it do its thing? Read on to understand what to expect if you choose to grow cannabis indoors au naturel, along with a few tips and tricks from experts to help your indoor plant thrive in a minimal setup.
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.
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].”
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.)
Trigger the flowering cycle.
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 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.
Plant and maintain the vegetative cycle until the plant is mature.
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.”
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.