Nick Hice, cultivation facility manager at Denver Relief, harvests several of the plants, getting them ready for the drying process. (Kathryn Scott Osler, The Denver Post)

Want to grow your own weed at home? Some basics

So you want to grow pot. Or you’re worried the neighbors will.

Marijuana is the botanical conversation piece that just won’t go away. Reactions to it run a wild gamut: It’s the evil weed or a source of future state tax revenue and entrepreneurial ingenuity. Or it’s the only path left to freedom from pain for some people, and journalists should write about it with the same seriousness that they accord blood-pressure medicine.

If you’re 21 or older, Amendment 64 allows you to cultivate up to six marijuana plants in an “enclosed, locked space” in Colorado. (This is still illegal under federal law.)

UPDATE: Governor’s pot panel recommends allowing only indoor growing

Sounds simple. But growing marijuana isn’t easy, those who do it professionally say.

Growing cannabis from seed is possible but impractical.

Such activities are subject to federal prosecution.

One thing is certain: Legalization is changing the landscape of our state. Maybe not our yards, but surely our headspace, our parties, our neighborhoods and our lives. If we understand the plant, it will help us talk about that change using facts rather than fear or naive enthusiasm.

We went to experts with the questions we felt any gardener and homeowner would have. Our interviewees for this story and video were Kayvan Khalatbari and Nick Hice, co-owners of Denver Relief, a medicinal-marijuana dispensary whose growing facility is home to about 1,900 marijuana plants.

An overview of the basics

Question: Where can Coloradans grow marijuana plants? Can people just stick them in a sunny window next to basil and aloe?

Answer: A big thing to remember with marijuana plants is that they need to flower to produce THC ( tetrahydrocannabinol, the chemical that gets people high) and other medicinal cannabinoids. In order to do that, they need 12 hours of light and 12 hours of total darkness a day.

So the best place to grow marijuana is in a room in the basement with a locked door so light doesn’t inadvertently get in when the plants are “sleeping.” If you don’t have a basement, a small closet with light-leak protection around the door will work.

Q: Is special growing equipment required?

A: All sorts of prepackaged items are available, like grow boxes or grow tents, that are probably best for a small space like a closet, or fo r someone who doesn’t want to get into growing marijuana too intensely.

But if you’re trying to get six plants to be as robust as possible, you probably need to install something that’s more permanent, like a 400- to 600-watt lamp with a hood assembly that comes with a ballast, which you place at least a forearm’s length above the plants.

Keep in mind that the ballast is going to get very hot, so you need to have adequate cooling in the room as well, like a portable air conditioner with a thermostat. You don’t want the room to get above 80 degrees because the hotter it is, the slower the plants grow. The ideal temperature is 75 to 80 degrees when the lights are on and 68 to 74 degrees when the lights are off.

You also have to watch humidity, because every time you water plants in a small space, you’re going to get high humidity. It should be below 50 percent to prevent bud mold or rot.

You can measure humidity with a hygrometer from a hardware or grow store, and reduce it with a dehumidifier or air conditioner.

Q: How would a home grower comply with the rule that limits them to three plants in flower?

A: That means you can grow only three plants if you don’t have two separate growing areas. The reason having only three plants is bad is that you want to keep a rotation going. Or else every time you get done harvesting, you have to go back to a store. If you want a continual supply, you want the perpetualness of having a vegetative stage and a flowering stage going all the time.

Logistics and costs

Q: How much does all this stuff cost?

A: Most grow boxes are $200 to $400, but if you want one with HVAC temperature-control capabilities, it’s pretty pricey — close to $1,000. You can find grow boxes at most local hydroponic stores or grow shops.

A light system and building materials will run $350 to $1,000, and electricity costs per harvest are $100 to $200.


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Q: Where would a home grower get seeds?

A: I actually never recommend starting a marijuana plant from seed, because you have to determine whether the seeds are male or female, which is difficult. Only female plants produce the flowers that are most desirable in terms of cannabinoid content. Male plants are pretty much unusable (for smoking purposes).

The best thing to do is to buy a clone — a cutting from a proven plant. People who have red cards (medical-marijuana cards) can buy clones from medical-marijuana centers and grow their own plants. If you know somebody who grows, it is legal today (under state law) for a 21-year-old (or someone older) with a marijuana plant in Colorado to give another 21-year-old (or older) a clone from that plant.

Read more: cannabis botany 101

This story was first published on DenverPost.com