Passionate Gardener: With Companion Planting, Marigolds Are Just the Beginning

Ron Kushner, for the Shuttle

Some plants just naturally enjoy a relationship as they grow in close proximity to each other. Roots growing at different levels allow some plants to thrive together since they are not competing for nutrients or water. Light requirements are equally helpful in confirming which plants can grow together, needing similar conditions. Companion plants tend to supplement each others’ needs by other means as well, including attracting and repelling insects and providing ground cover to keep the soil moist, not to mention keeping weeds down.

Try any of the following combinations in your garden to provide not only better yields but an aesthetic appeal during those times of the season when our gardens don’t look their best.

Asparagus is one vegetable usually contained in its own plot or area and generally planted alone. True, other plants would tend to get lost in the thick, tall fronds in the middle of the asparagus bed, but the borders can be planted successfully. Use any combination of annual herbs such as basil, dill, coriander or parsley. Tall annual flowers like cosmos and sweet Annie also work well. Edging plants like nasturtium, salad greens and calendula are another nice idea. Calendula (“pot marigold”) tends to deter asparagus beetles. I’ve read quite a bit about tomatoes being good companion plants to asparagus, and although I’ve never seen them grown together, tomatoes also tend to repel asparagus beetles.

Beans grown with potatoes reduce problems with Mexican bean beetles and Colorado potato beetles; this has been confirmed in recent studies through the Cornell Cooperative Extension. If you can plant goldenrod, dill or tansy nearby, their flowers attract spined soldier bugs and certain wasps that will eat bean beetles. Beans also do well interplanted with beets, cabbage, carrots and cauliflower. Do not plant beans with chives, onions or shallots, as they tend to inhibit bean growth. Pair beans with peas as they are in the same family and have similar needs. Plant also with corn, cucumber, squash and eggplant.

Beets will grow with other root crops, such as onions and carrots, as well as with cabbage and kohlrabi. Or try planting them with salad greens as they can be harvested with the beet greens. Pots of catnip or mint nearby help repel flea beetles.

Cabbage family plants all love to grow together: cabbage, Brussels sprouts, broccoli, cauliflower, kale and Chinese cabbage. Borage is an excellent companion, protecting these crucifers from some common pests. Other good companions are celery, chamomile, dill, mint, parsley, rosemary, sage, zinnias, asters and marigolds. It’s also a good idea to under-plant with a thick seeding of sweet alyssum to block weeds and attract beneficial insects, particularly syrphid flies. All cabbage family plants can be planted with beets, onions and potatoes.

Carrots can be planted with onions and related crops such as chives as they tend to repel (or at least confuse) the carrot rust fly. They can also be planted with other root crops like beets and radishes. Marigolds, fennel, chamomile and herbs such as caraway and coriander are great companions. Coriander (cilantro) is a favored annual among a variety of beneficial insects including lady beetles, green lacewings and parasitic wasps.

Cucumbers can be planted with squash, cabbage, lettuce, beans and spinach. Nasturtiums provide shelter for beneficial spiders and ground beetles. Interplant with radishes and marigolds. The radishes repel striped cucumber beetles and squash borers. Borage is said to improve their flavor!

Tomato, eggplant and peppers all do well with basil, dill, borage and parsley. Companion flowers include asters, cleome, cosmos, marigolds and nasturtium. But do not plant fennel near tomatoes, eggplant or peppers.

Growing a diversity of companion plants that offer a succession of blooms from early spring through fall will help keep beneficial insects in your garden, not to mention the varieties of color and texture that will make your garden look great all season long.