Some plants grow well together. Others do not. The companion relationships between plant species are greatly influenced by what nutrients each plant derives from the soil, the amount of moisture they need from the soil, the general condition of the soil and what each plant releases into the soil. Selecting companion plants is based upon the success others have had with growing certain plants together, and companion planting allows the plants to benefit from each others' presence in the same soil.
A companion to other herbs, such as sage, peppermint, dill and chamomile, rosemary and these very same herbs are good companions for many vegetables, including onions, beans, cabbage, broccoli, kale, carrots, kohlrabi, turnips and celery. All of these herbs and vegetables are good companions to each other as well. Rosemary repels the Mexican bean beetle, slugs and snails.
Besides enjoying their aromatic scents and herbal properties, mint plants well in a garden alongside tomatoes, cabbage, roses and potatoes. Plant mints in your garden to repel ants, aphids, flea beetles, imported cabbageworms, squash bugs and whiteflies.
The squash family favors the companionship of its own members, including pumpkin, butternut squash, watermelon, cantaloupe, cucumbers and zucchini, and they are all good companions to corn, beans and peas. Squashes enjoy a little shade, and the height of the corn provides this. The squash family of vegetables also benefits from neighboring borage, nasturtium and radish, and the nasturtium repels aphids, asparagus beetle, cabbage looper, Colorado potato beetle, cucumber beetle, flea beetle, imported cabbage worm, Japanese beetle, squash bug and the whitefly.
Carrots, parsley, onion, celery, chives, asparagus and the flowers marigolds, roses and nasturtiums are good companion plants for tomatoes. Basil, dill, mint and peppers are also companion plants for tomatoes. Tomatoes repel asparagus beetles, and plant marigold in between the plants also repels beetles.
Grow oregano near your pumpkin patches, cucumbers, grapes, cauliflower, cabbage and broccoli. Oregano is a general pest repellent in the garden.
Enhance your strawberry patch with companion plants that help your strawberry plants grow healthy and strong: tomatoes, squashes, beans, borage, lettuce, spinach, onions, cabbage, thyme, eggplant, sage and potato make good companions to strawberries.
Beans do well when planted alongside sunflowers, corn, beets, peas, radishes, butternut squash, yellow squash, zucchini and cucumbers, as well as cauliflower, strawberries and carrots.
Besides its companionship to tomatoes and carrots, plant parsley near chives, asparagus, carrots, tomatoes and roses. Parsley in the garden repels the asparagus beetle.
In addition to strawberries and rosemary, sage helps the growth of tomatoes, peas, beans, carrots, cabbage, rosemary, marjoram and other herbs. Sage in the garden also repels the carrot fly, cabbage looper and the imported cabbageworm.
Planting herbs throughout your garden not only adds interesting contrasts of colors and textures, but they also help the growth of their companion plants. Chamomile grows well with many other herbs, as well as onions, melons and cabbage.