Organic gardeners know that a diverse mix of plants makes for a healthy and beautiful garden. Many believe that certain plant combinations have extraordinary (even mysterious) powers to help each other grow. Scientific study of the process, called companion planting, has confirmed that some combinations have real benefits unique to those combinations. And practical experience has demonstrated to many gardeners how to mate certain plants for their mutual benefit. Companions help each other grow—tall plants, for example, provide shade for sun-sensitive shorter plants. And the technique uses garden space efficiently. Vining plants cover the ground, upright plants grow up, allowing for two plants in the same patch. Companions also prevent pest problems. Plants like onions repel pests and other plants can lure pests away from more delicate plants. Or one plant may attract the predators of another plant's pests.
Roses And Garlic
Gardeners have been planting garlic with roses for eons. since garlic can help to repel rose pests. Garlic chives probably are just as repellent, and their small purple or white flowers in late spring looks great with rose flowers and foliage.
Tomatoes And Cabbage
Tomatoes are repellent to diamondback moth larvae, which are caterpillars that chew large holes in cabbage leaves.
Cucumbers And Nasturtiums
The nasturtium's vining stems make them a great companion rambling among your growing cucumbers and squash plants, suggests Sally Jean Cunningham, master gardener and author of Great Garden Companions. Nasturtiums "are reputed to repel cucumber beetles, but I depend on them more as habitat for predatory insects," such as spiders and ground beetles.
Peppers And Pigweed
Leafminers preferred both pigweed and ragweed to pepper plants in a study at the Coastal Plains Experiment Station in Tifton, Georgia. Just be careful to remove the flowers before the weeds set seed.
Cabbage And Dill
"Dill is a great companion for cabbage family plants, such as broccoli and brussels sprouts," Cunningham says. "The cabbages support the floppy dill," while the dill attracts the tiny beneficial wasps that control imported cabbageworms and other cabbage pests.
Corn And Beans
The beans attract beneficial insects that prey on corn pests such as leafhoppers, fall armyworms and leaf beetles. And bean vines climb up the corn stalks.
Lettuce And Tall Flowers
Nicotiana (flowering tobacco) and cleome (spider flower) give lettuce the light shade it grows best in.
Radishes And Spinach
Planting radishes among yor spinach will draw leafminers away from the spinach. The damage the leafminers do to radish leaves doesn't prevent the radishes from growing nicely underground.
Potatoes And Sweet Alyssum
The sweet alyssum has tiny flowers that attract delicate beneficial insects, such as predatory wasps. Plant sweet alyssum alongside bushy crops like potatoes, or let it spread to form a living ground cover under arching plants like broccoli. Bonus: The alyssum's sweet fragrance will scent your garden all summer.
Cauliflower And Dwarf Zinnias
The nectar from the dwarf zinnias lures ladybugs and otherpredators that help protect cauliflower.
Collards And Catnip
Studies have found that planting catnip alongside collards reduces flea-beetle damage on the collards.
Strawberries And Love-In-A-Mist
Tall, blue-flowered "love-in-a-mist (Nigella damascena) looks wonderful planted in the center of a wide row of strawberries," Cunningham says.
Marigolds And Melons
Certain marigold varieties control nematodes in the roots of melon as effectively as chemical treatments.