I transplant clones into a one-gallon container because they are easier to move indoors on cold nights. Later I transplant them into a 5-gallon container. (Photo courtesy Jorge Cervantes)

Yes, cannabis grows like a weed — but there are limits to simplicity

Cannabis Cultivation Q&A: If you're looking for results by growing a marijuana plant in a plastic cup in a sunny window, better set your expectations low

Renowned grower Jorge Cervantes will answer readers’ questions and give advice on all things related to the cannabis plant. Got a question for Jorge? Email him at jorge@marijuanagrowing.com.

Editor’s Note: Laws for cultivating cannabis vary from state to state and city to city — before germinating any seeds or planting any clones, take care to learn what your local laws are.


Question: If I plant a seed or a clone in a Solo cup, give it some water and stick that cup in a sunny window — will it still grow and flourish and produce flowers? I like the idea of growing at home, but I don’t like the idea of investing hundreds in grow lights and nutrients and timers and such. So can this simple way of growing yield results?

Answer: Yes, it grows like a weed! Your scenario will yield results, but the poor little plant will likely be limited by access to sunlight and a dinky container. A bigger container of soil, more warm sunlight and good ventilation will help her grow big and strong.

Growing cannabis outdoors (where legal) is inexpensive, fun and a bit of work. Temperature is the main concern in cool climates, especially mountainous regions. You will need to start the plant indoors and move it outdoors to full sun during the days and bring it in on cool nights that dip below 40 degrees F.

Go to a local medical cannabis dispensary or a retail cannabis outlet to find strong clones. I just did a search on the internet and found many outlets in Colorado and other states where home cultivation is allowed. Shop around and ask for clones that will flower early and that grow well outdoors. The sales clerk will know more about local varieties available.

Clones can be expensive ($20-$40 each). Pamper your valuable clones by growing them in top-quality potting soil and 5- to 10-gallon containers. You can grow in big 200-gallon containers, but they are expensive to fill with soil. Growing in smaller containers allows you to move them indoors when it is cold and weather is bad.

Transplant the clones into the quality potting soil in the 5-gallon containers. Water them in until soil is saturated. Place the pots outdoors in the shade. Bring plants in if temperatures dip below 40-50 degrees F.

Set the transplanted clones in the shade for a few days so that they will get used to the new soil and climate. They will be shocked both from the change in soil environment and from the outdoor weather. In a few days the little girls should perk up a bit. Now you can place them in direct sunlight for a couple of hours a day. Each day, set little clones in direct sunlight for a longer period. By the end of the week, the girls should be able to take full sun all day long. This process is called “hardening off.” Plants need a minimum of 5 hours of direct sunlight to produce compact, dense flower buds. Plants that receive more sunlight grow bigger and stronger.

The next phase is to care for your plants like you would any other annual. Regular watering and periodic fertilizing is in order. Water soil heavily until water freely runs out the bottom of the pot. Make sure water penetrates all soil. Get a feel for the moisture level — water when soil is dry down to your second knuckle, or when containers weigh half as much as they do after watering.

Organic fertilized cannabis has a superior aroma and taste. Toss in a handful of chicken manure after plants have been growing a month. Do not start sooner unless bottom leaves yellow.

Always follow local laws! Do your homework!

Stay tuned for information on flowering and harvesting, and check The Cannabist’s cultivation section for more tips.

This has been a whirlwind tour of growing a few cannabis plants. I’m going pretty fast and simplifying it all. Please check out my YouTube channel, where you can find hands-on videos on transplanting and all other phases of gardening.