Container gardening is a common practice for growing houseplants that range from orchids to cactus indoors. Containers are also utilized on balconies and terraces to grow plants that range from trees and shrubs to vegetables. Container gardens using vegetables are an easy way for a gardener to grow plants when space is limited, or the gardener is older, handicapped or otherwise limited in mobility. Any plant that will grow in the ground can be adapted to container culture.
Select the appropriate container for the vegetable that you wish to plant. You can raise fast-growing vegetables with shallow roots such as green onions in a 1-gallon container, while a large, bushy plant such as a tomato vine requires at least 5 gallons of soil in which to thrive. Clay containers are porous and require more frequent watering than plastic containers.
Read the labels of potting soil mixes before purchasing potting soil for your containers. Potting soil should contain a balanced fertilizer blend (10-10-10) and should be sterilized. Never use dirt in your containers. Dirt is filled with microbes that can multiply in a container to the point that they damage your plants. Choose a soil that is lightweight and contains a good ratio of sand or vermiculite.
Start seeds in potting trays before transplanting them into containers, or purchase transplants from a garden center. To start seeds in potting trays, fill a potting tray with peat moss. Hollow out a planting pocket for your seed with the point of a pencil. Seeds should be planted twice as deep as the seed's thickness at the widest point. Mist the peat moss with water and cover with plastic. Place the tray in a sunny windowsill to help the seedlings germinate. Remove the plastic and continue to water the plants.
Place a pottery shard over the drainage hole of each container so that soil does not erode from the container along with extra water when you water your plants. Fill your container with potting soil.
Place the potting tray outdoors in shade during daylight hours and move them back indoors for three days so that they can harden off. Then slip each seedling out of the potting tray. Hollow out a planting hole in the potting soil in your container and place the transplant in the planting hole. Fill in the sides of the planting hole with soil. Keep the soil of your container as moist as a wrung-out sponge.