Some things just go together; peanut butter and jelly, March and basketball, nasturtiums and cucumbers? Over the winter I've been doing a lot of reading on companion plantings. These are two or more kinds of plants when situated together are mutually beneficial. In planning my vegetable garden I may as well try to plant things that make each other happy.
The most famous companion planting is the Three Sisters (corn, beans and squash) planted together in Meso-American societies. The beans fixed nitrogen, thus improving the soil for the corn. The corn provided shade and a trellis for the squash and beans, and the prickly squash vines deterred raccoons and other pests from eating the corncobs.Companion plantings usually deter pests, improve yield, or provide another physical benefit, such as shade or structural support.
Scent has a lot to do with it. Some of the literature suggests that strong odors disorient insects preventing them from finding crops they like to munch on. The pungent odor of garlic or onions deters lots of pests. Aromatic herbs like lavender, mint, sage, and catmint, are also good protection. Some herbs like thyme, chamomile and savory attract predatory insects that hunt destructive garden pests.
Some companions act as trap plants. Collards planted near cabbages and broccoli will attract diamondback cabbage worms, usually so destructive to those crops. Eggplants will trap Colorado potato beetles, leaving the potatoes alone. These trap plants can be sprayed, leaving your desirable plants chemical-free.
One of my favorite annuals, nasturtiums, not only has edible spicy flowers and blooms well into the fall, but also deters whiteflies, squash bugs and cucumber beetles. It is a great one to plant around tomatoes, cabbage and cucumbers.
Marigolds also deserve a place in the vegetable garden, especially pungent ones. Their scent deters bean beetles and fleas, and their roots repel nematodes.
Tomatoes have lots of friends. Basil when planted with tomatoes, improves the flavor and vigor of each. Lettuces go well with tomatoes, as the larger tomato plants will shade heat-sensitive lettuce, prolonging its cutting season.
There are also groups of plants that shouldn't be planted together as they inhibit growth or attract detrimental insects. Keep tomatoes and corn apart, as the worms that attack each are similar.
Potatoes are more succeptible to potato blight when near tomatoes. Don't plant members of the cabbage or nightshade families near your strawberry patch as all groups are attacked by verticillium wilt. Onions stunt the growth of peas and beans.
While all of the scientific reasoning behind companion planting hasn't been totally worked out, there was a cockamamie theory that found favor in the middle of the 20th century. Different plants were ground up and put into solution. The crystal structures formed by heating and cooling different plant solutions together were judged to be complementary or adversarial. Don't forget, people once tried to make gold from lead, too.
Google "companion plantings" and you'll get pages of charts of plants that do well together. If you are new to gardening, or an experienced hand, some of these combos are worth a try.



