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

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

     Cabbage

    Dill, Mint, Onions, Rosemary, Sage, Thyme

    		   

     Caraway

    Plant throughout the garden to loosen the soil.

     

    Dill

     Carrots

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

    		   

     Catnip

    Eggplant

    Flea Beetle, Ants

    		 

     Chamomile
    Keep thinned.

    Cabbage, Onion

     

    		 

     Chervil;

    Radish

     

    		 

     Chives

    Carrots, Roses

    Aphids, Mites, Nematodes

    		 

     Coriander

     

    Aphids

    		 

     Corn

    Beans, Cucumbers, Melons, Peas, Potatoes, Squash

    		  Tomatoes

     Cucumbers

    Cabbage, Corn, Lettuce, Marigolds, Onions, Radishes

    		   

     Dill

     Cabbage, Lettuce, Corn, Cucumber

    Aphids, Mites

    		 

     Feverfew

    Roses

    attracts aphids away from roses

    		 

     Flax

    Carrots, Potatoes

    Potato Bug

    		 

     Garlic

    Roses, Raspberries

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

    		 

     Horseradish

    Potatoes

    Potatoe Bug

    		 

     Hyssop

    Cabbage, Grapes

    Cabbage Moth

    Radishes

     Lavender

     

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

    		 

     Lettuce

    Beets, Cabbage, Carrots, Onions, Radishes

    		   

     Marigold

    Most Plants, Especially Tomatoes,

    Nematodes, Whiteflies, Mexican Bean Beetles, Tomato Hornworms

    		 

     Mint

    Cabbage, Tomatoes

    Cabbage Moths, Aphids, Ants, Flea Beetles

    		 

     Nasturtiums

    Cabbage, Radishes, Tomatoes, Cucumbers

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

    		 

     Onions

    Beets, Cabbage, Lettuce, Tomatoes

    Borers, Mites, Slugs, Cutworms

    Beans, Peas

     Peas

    Beans, Carrots, Corn, Cucumbers, Radishes, Turnips

    		 

    Onions, Garlic

     Pennyroyal

    Roses

    Flies, Mosquitoes, Fleas, others

    		 

     Peppers

    Basil, Marjoram, Oregano, Carrots, Tomatoes

    		   

     Petunia

    Beans

    Aphids, Leafhoppers, Mexican Bean Beetles

    		 

     Radishes

    Peas, Leaf Lettuce

    Cucumber Beetles

    		 

     Rosemary

    Beans, Cabbage, Carrots, Sage

    Carrot Flies, Cabbage Moths, Mexican Bean Beetles

    		 

     Rue

    Roses and Raspberries

    Japanese Beetles

    Sweet Basil

     Sage

    Cabbage, Carrots, Cucumbers, Tomatoes, Rosemary

    Cabbage Moths, Flea Beetles, Slugs

    		 

     Spinach

    Cabbage

    		   

     Squash

    Corn, Cucumbers

    		   

     Summer Savory

    Beans

    Bean Beetles

    		 

     Tansy

    Fruit Trees, Roses, Raspberries

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

    		 

     Tomatoes

    Basil, Sage, Marigolds, Nasturtiums, Asparagus

    		   

     Thyme

    Cabbage

    Cabbage Worms

    		 

     Wormwood

     

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

    		 

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