Vegetable garden companion plants can be herbs, flowers, fruits or other vegetables. Companion plants are two or more plants that grow better planted next to each other. Typically, gardeners choose companion plants because one offers the other protection by repelling an insect that would damage the crop. For example, radishes planted with cucumbers help deter the cucumber beetle, making these two crops good vegetable garden companion plants.
The bean beetle is a major pest in many gardens. Marigold, nasturtium and summer savory planted around bean plants help deter the bean beetle. Summer savory improves the growth and flavor of beans, both bush and pole types.
Sunflowers are good vegetable garden companion plants for beans because they grow taller. Beans appreciate a bit of shade from the sunflowers, not to mention the sunflowers attract birds and bees. The birds will eat flying insects and the bees will pollinate the beans.
Other vegetable garden companion plants for beans include members of the cabbage family, carrots, celery, chard, corn, cucumber, eggplant, peas, potatoes, radish, strawberries, and for bush beans only, beets.
The three sisters garden, made famous by the Iroquois Indians, contained corn, beans and squash.
Corn is high in calories and provides energy, making it a staple crop. The stalks make the perfect natural pole for beans to grow up. Corn is a heavy feeder that benefits from growing in fertile soil.
Beans fix nitrogen on their roots and improve the fertility of the soil. The beans help the corn by anchoring them to the ground, making the corn stalks less vulnerable to wind damage.
Squash is a shallow-rooted crop. As vegetable garden companion plants, squash provides a living mulch, offering shade to the corn and bean roots and helping to keep the soil underneath moist. The vines of the squash plants help deter raccoons and other critters that might otherwise eat the corn or beans. The reason for this is the critters get tangled in the vines. Some squash plants are also spiny, which can be even more of a deterrent.
To deter Japanese beetles, plant some white geranium and odorless marigolds on the outside edge of the three sisters garden.
Vegetable garden companion plants for tomatoes include carrots, basil, chives, onion, parsley, asparagus, marigold, nasturtium, sage, bee balm, chives, mint and borage.
Basil, asparagus and tomato planted in the same bed have a very beneficial effect on all three plants. The basil repels the tomato hornworm, flies and mosquitoes, while improving the flavor of the tomatoes. Asparagus repels pests that would bother the tomato plants as well.
Borage helps deter the tomato hornworm. Marigold flowers deter nematodes and mint improves the overall flavor of tomatoes.