According to the Maryland Cooperative Extension, container gardening is a good solution for gardening in small spaces, for growing plants in areas where the soil is poor or for gardeners who have little free time to work the soil of a garden bed. Although you can purchase containers for your garden, the expense of purchasing large containers for an extensive garden may be more than you wish to undertake. Instead, you can convert items into patio containers with little effort. The key is to know your container needs and have a design in mind while you look.
Select boxes, pots, barrels and buckets that will hold at least 5 gallons of soil. This is the minimum requirement for plants so that the roots can spread out and thrive.
Pick out containers that are light in color. Darker containers will heat the soil and injure the roots of your plants. For containers such as old tires, you can paint the exterior with a light-colored latex paint to keep the container from absorbing light and becoming hot.
Turn your containers over and drill ½-inch drainage holes in the underside of the containers. This will prevent plants from becoming waterlogged.
Mix one part sand, one part peat moss, two parts compost and half a part of well-rotted manure in a bucket using a garden trowel to form a lightweight, nutrient-rich soil for your container.
Place a pottery shard over each drill hole in the bottom of your container to prevent potting soil from washing out through the drainage holes.
Fill your container with potting soil up to within an inch of the top of the container. Hollow out a pocket of air in the center of a container to create a planting hole.
Fill your pots with vegetable seedlings you purchased from a garden center or started from seed indoors. Place a single plant per 5 gallons of soil. Accordingly, 10-gallon containers may hold two plants, and 15-gallon containers can hold three plants. Space each plant equidistant from its neighbor.