Companion Planting - Tarrant County, Texas Cooperative Extension

1. Tarrant County Horticulture Office
401 East Eighth Street
Fort Worth, Texas 76102
817-884-1944/FAX 817-884-1941
Companion Planting
In organic gardening we attempt to duplicate nature. In nature there is a diverse
variety of vegetation within a given area. Without our interference these plants seem to
thrive without being overtaken by pest or disease. Why is it that certain vegetation exists in
harmony together? Many of the exact answers are unknown or undefined, yet that does not
mean that reasons do not exist. A companion that is a positive influence in one area or
region may present problems in another. Recent high temperatures may turn a good plant
choice into a poor plant choice. (A hybrid plant may look better, but may not have charac-
teristics, scent, taste, or enzyme chemical production that make them suitable for organic
gardening).
Keen observation is recommended so that the grower observes whether the results
come true to form in that particular growing micro-system. If the companion plant creates a
problem that spreads beyond the companion plant, then remove the companion plant. To
companion plant a trap crop and then spray pesticide to protect other crops is inviting an
abundance of pests with no natural enemies. Ultimately, we have created a damaging
situation rather than a situation that is balanced.

2. PLANTS THAT REPELL PESTS
Ants Penny Royal, spearmint, Southern Wood, Tansy, peppermint, wormwood
Aphid catnip, chives, coriander, eucalyptus, fennel, garlic, larkspur, marigold, mustard,
nasturtiam, peppermint, spearmint, anise, petunia
Asparagus beetle tomatoes, basil, parsley
Borer Garlic, tansy, onions
Cabbage butterfly dill, eucalyptus, garlic, hyssop, peppermint, nasturtium, onion, Penny Royal,
sage, southern wood, spearmint, thyme, wormwood
Cabbage maggot mint, tomatoes, Rosemary, sage, garlic, marigold, radish, wormwood
Cabbage moth mint, hyssop, Rosemary, southern wood, thyme, sage, wormwood, celery, catnip,
nasturtium
Codling moth garlic, wormwood
Carrot fly leek, lettuce, onion, Rosemary, sage tobacco, wormwood, black salsify, coriander
Chinch bug Soy beans
Colarado potato beetle green beans, horseradish, dead nettle, flax, catnip, coriander
Corn earworm cosmos, geranium, marigold
Cucumber beetle catnip, marigold, nasturtium, radish, rue tansy
Cutworm tansy, spiny amaranth
Flea beetle catnip, peppermint, rue, spearmint, southern wood, tansy, tobacco, wormwood,
cole crops with tomatoes
Fruit tree moth Southern wood
Imported cabbage dill, garlic, geranium, hyssop, peppermint, nasturtium, onion, Penny Royal, sage,
worm southern wood, tansy, thyme
Japanese beetle garlic larkspur (poisonous to humans), tansy, rue, geranium (white works best),
catnip, chives
Gopher caster bean
Leaf hopper Geranium, Petunia
Mexican bean beetle Marigold, Rosemary, savories, potatoes, Petunia
Mice mint, wormwood
Mole caster beans, narcissus
Nematode Marigold(African and French varieties), Salvia (Scarlet sage), Dalhia, Calendule,
pot marigold, asparagus, cereal rye
Peach borer garlic
Plum curculio garlic
Rabbit garlic, Marigold, onion
Slugs and Snails fennel, garlic, Rosemary (prostrate), wormwood
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3. Spider mite coriander
Squash bug catnip, nasturtium, peppermint, Petunia, radish, spearmint, tansy
Squash vine borer radish
Striped pumpkin beetle nasturtium
Tomato hornworm borage, Marigold, opal basil, dill(trap crop)
White fly nasturtium, Marigold, nicandra (Pervian ground cherry) peppermint, thyme,
wormwood
Wireworm white mustard, buckwheat
MOST BENEFICIAL LIST
The 12 Top Repelling Plants in Order
1. Wormwood 7. Marigold
2. Garlic 8. Onion
3. Nasturtium 9. Catnip
4. Tansy 10. Southern wood
5. Spearmint 11. Sage
6. Peppermint 12. Coriander
Also should be considered:
Chives Penny Royal
Radish Rue
Dill Petunia
Rosemary Royal
Petunia
ENEMY HERBS
Herbs Plant it Harms
Anise Carrot
Chives Beans, peas
Chrysanthemum Lettuce
Coriander Fennel
Dill Carrot and tomatoes
Fennel Beans and pepper
Garlic Beans and pea
Larkspur Beet
Mustard Turnip
Onion Bean, pea, sage
Rue Basil, cabbage, sage
Sage Onion
Tansy Collard
Wormwood Most vegetables
Souces: Encyclopedia of Organic Gardening, Rodale Press; How to Grow More Vegetables, John Jeavons; Illustrated Encyclopedia of Herbs,
Rodale Press
T he information contained in this publication is not based on research conducted at T exas A&M or with the T exas Agricultural Extension Service. It is, however, a compilation of
information from several organic gardening sources. Information compiled by D ee W heeler, Tarrant County M aster G ardener
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