Just about any plant that can be grown in the garden can be grown in a container as well. Any container will work, as long as it has holes in the bottom for drainage and is large enough to allow room for roots to grow without crowding.
Before choosing your containers, decide what plants you will grow, and make a list of the containers you might use for each. Clay pots in a range of sizes, for example, are suitable for most herbs and small flowers. Window boxes or other shallow containers with wide openings work well for lettuce and spinach. Half-barrel sized containers are suitable for root crops like potatoes and carrots. Tall plants like tomatoes, which thrive when allowed to develop deep root systems, prefer deep containers such as 5-gallon paint buckets.
Armed with your list, purchase the needed containers or be resourceful and gather suitable items to repurpose from around the house. Choose the location for your containers based on the amount of light that is available. The containers will need at least six hours of full sun each day. Group them with an eye toward complimentary heights and colors, and be sure any vining plants are placed where they will have supports on which to climb.
Use a lightweight potting mix along with compost to fill your containers after you’ve moved them to their permanent location. The lightweight mix promotes air and water circulation beneath the soil and lets roots grow freely. Filling the pots after they’re positioned saves you from having to move them when they’re heavier. Sow seeds or transplant seedlings into the pots when temperatures have reached the appropriate range for the specific plants’ needs.
One difference between in-ground and container gardening is that containers require more frequent watering. Check them daily and water as needed to keep soil adequately moist. Soil in clay pots will dry more quickly than glass or plastic containers, since the porous clay allows the air to leech moisture from the soil more readily.
You’ll need to observe container garden feeding instructions for the fertilizer you intend to use. Rapid growth and frequent watering deplete nutrients from the soil more quickly than in garden beds. Water-based commercial fertilizers have to be re-applied every two to three weeks.