Companion Plants

Companion planting involves nothing more than arranging the plants in a garden in such a way that they enhance the growth and quality of nearby crops, provide maximum ground cover, and, if possible, improve the soil. Companion plants are also one of nature's ways of controlling insects populations. Fragrant flowers and herbs drive away pesky garden insects. For example, an annual with a strongly fragranced leaf and blossom that insects find appalling is the marigold. Not only does its strong odor literally confuse pests looking for their favorite plants, but their roots give off a substance which repels nematodes. Planting a couple of rows of marigolds around the edge of your garden will add both beauty and a measure of protection for your vegetables.

A useful trick here in the Valley is to plant garlic in your garden beds and around the base of fruit trees to repel Japanese Beetles.

Although much of our knowledge of companion plants is based in folklore, science has gathered enough evidence to support the following:

  • Plants with strong odors do confuse, deter, and oftentimes stop certain pests.
  • Certain plants hide other certain plants we don’t want detected.
  • Certain plants, and especially herbs, are considered nursery plants for the good insects providing shelter, nectar, pollen, and even dark, cool moist spots for lacewings, lady beetles, parasitic flies, and wasps.
  • Certain plants serve as a “trap” crop, which pushes insects away from other essential plants (rue’s bad odor and disagreeable taste will keep even the most persistent of pests away).
  • Certain plants create habitats which attract more beneficial insects (such as lady beetles, praying mantis, and ambush bugs).
  • Among the most popular of repellent plants are garlic and chives because of their powerful ability to repel aphids and beetles. Similarly, savory, chamomile, and thyme are ideal planting crops. These three herbs will attract more beneficial insects than any bright, pretty flower will. So when you’re planning your summer garden, include plenty of each.

    For more information about companion planting:
    ANR-1045   Garden Bugs

    You Can Plant This

    With These Plants

    To Help Repel These

    But, Do Not Plant With These

    Mosquitoes, Flies,  Hornworms
    Beets, Cucumbers, Corn, Radishes, Rosemary
      Onions, Garlic
    Bush Beans, Cabbage, Lettuce
    Tomatoes, Squash, Strawberries
    Tomato Worm
    Herbs, Onions


    Dill, Mint, Onions, Rosemary, Sage, Thyme



    Plant throughout the garden to loosen the soil.




    Peas, Cabbage, Leaf Lettuce, Radishes, Tomatoes, Chives




    Flea Beetle, Ants


    Keep thinned.

    Cabbage, Onion








    Carrots, Roses

    Aphids, Mites, Nematodes







    Beans, Cucumbers, Melons, Peas, Potatoes, Squash



    Cabbage, Corn, Lettuce, Marigolds, Onions, Radishes



     Cabbage, Lettuce, Corn, Cucumber

    Aphids, Mites




    attracts aphids away from roses



    Carrots, Potatoes

    Potato Bug



    Roses, Raspberries

    Japanese Beetles, Aphids, Mosquito Larvae, Caterpillars, Borers, Mites




    Potatoe Bug



    Cabbage, Grapes

    Cabbage Moth




    Moths -- combine with southernwood, wormwood and rosemary in an anti-moth sachet



    Beets, Cabbage, Carrots, Onions, Radishes



    Most Plants, Especially Tomatoes,

    Nematodes, Whiteflies, Mexican Bean Beetles, Tomato Hornworms



    Cabbage, Tomatoes

    Cabbage Moths, Aphids, Ants, Flea Beetles



    Cabbage, Radishes, Tomatoes, Cucumbers

    Aphids, Pumpkin Beetles, Squash Beetles, Cabbage Moths, Potato Beetles, Whiteflies



    Beets, Cabbage, Lettuce, Tomatoes

    Borers, Mites, Slugs, Cutworms

    Beans, Peas


    Beans, Carrots, Corn, Cucumbers, Radishes, Turnips


    Onions, Garlic



    Flies, Mosquitoes, Fleas, others



    Basil, Marjoram, Oregano, Carrots, Tomatoes




    Aphids, Leafhoppers, Mexican Bean Beetles



    Peas, Leaf Lettuce

    Cucumber Beetles



    Beans, Cabbage, Carrots, Sage

    Carrot Flies, Cabbage Moths, Mexican Bean Beetles



    Roses and Raspberries

    Japanese Beetles

    Sweet Basil


    Cabbage, Carrots, Cucumbers, Tomatoes, Rosemary

    Cabbage Moths, Flea Beetles, Slugs






    Corn, Cucumbers


     Summer Savory


    Bean Beetles



    Fruit Trees, Roses, Raspberries

    Flying Insects, Japanese Beetles, Striped Cucumber Beetles, Squash Bugs, Ants, Flies



    Basil, Sage, Marigolds, Nasturtiums, Asparagus




    Cabbage Worms




    Plant as a border to keep animals out of the garden.


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