To a certain extent your container selection will be determined by your marijuana garden location. For example, you won’t be using five-gallon containers indoors because they’ll take up too much room under the lights. In an indoor situation, one- or two-gallon pots are a better choice. Containers are essential for indoor marijuana growing, but I recommend them for outdoor cultivation as well because they’re easy to move around and conceal as your other outdoor plants grow and mature. (If you don’t have other outdoor plants, now is a good time to select and plant some as support for your marijuana garden.)
Although you can grow marijuana in any container that will hold soil and water, out-doors the best kind are the three- or five-gallon light plastic pots, the type that nurseries use for selling small trees and shrubs. Forget about pretty pots like decorated clay planters—they simply aren’t needed and will be concealed anyway, unless you feel confident in showing off your garden or have no guests. You could always paint the pots green or camouflage, if you think that will conceal them better.
The most important thing to consider with containers is drainage. Marijuana plants do not like their roots to be constantly flooded with water. In the three-gallon pots, make sure there are sufficient drainage holes—in other words, more than a single small hole. If the holes are larger than a half inch in diameter, plug them with stones just slightly larger than the holes to prevent the soil from washing out. Gravity and porous soil will ensure good drainage no matter how much water you give them.
You can start your small plants in smaller pots, like ones with a six-inch diameter, and then transplant them to increasingly larger pots if you wish. Marijuana plants produce a lot of roots that can quickly fill pots. This constricts the roots and the plants become root-bound. So, as the roots fill a pot and start working their way out of the drainage holes, transplant them to larger pots.
The good news is that marijuana is a hardy plant that can adapt to constricted roots in small pots as long as it has sufficient water and nutrients. If you have the room, after the seedlings grow to the optimum size, with three or four sets of leaves, transplant them to the pots you will use—smaller ones for indoors and three- to five-gallon pots for outdoors—and leave them there, saving yourself all the extra work of constantly repotting. While growers constantly debate the subject of constricted roots, I suggest you use the largest pots possible for your growing situation, whether it’s indoors or outdoors. I have seen vigorous and healthy flowering marijuana plants six feet tall in three-gallon containers, so that’s proof in itself that the plant is happy despite somewhat constricted roots. If you’re concerned about root constriction, use five-gallon pots if you have the room. The extra cost is minimal and watering frequency diminishes. More about this subject on this link.
