companion planting
Nitrogen Fixers
Nitrogen fixers are commonly planted as companion plants for their ability to convert atmospheric nitrogen into forms in the soil usable by other plants.
For maximum nitrogen returned to the soil, plant nitrogen fixers as cover crops that you chop and drop as mulch when at maximum flower, when the vegetation is at its maximum nitrogen content.
Examples include:
1. most legumes (Fabaceae - eg. clover, beans, alfalfa)
2. azolla (mosquito fern - Salviniaceae)
3. genus Trema (Cannabaceae)
4. actinorhizal plants that form a symbiosis with actinobacteria Frankia
Betulaceae
- genus Alnus (alder)
Coriariaceae
- genus Coriaria
Myricaceae
- genus Comptonia (sweetfern)
- genus Myrica (bayberry)
Elaeagnaceae
- genus Elaeagnus (silverberry/oleaster)
- genus Hippophae (sea buckthorns)
- genus Shepherdia (buffaloberry)
Rhamnaceae
- genus Colletia
- genus Discaria
- genus Kentrothamnus
- genus Retanilla
- genus Trevoa
- genus Ochetophila
- genus Ceanothus
Rosaceae
- genus Cercocarpus (mountain mahoganies)
- genus Chamaebatia (mountain miseries)
- genus Dryas
- genus Purshia (bitterbrushes)
5. cycads
6. genus gunnera (Gunneraceae)
7. some lichens, liverwort, and hornworts
Trap Crops
Trap crops are plants used as distractions for pests to protect more valuable crops.
1. alfalfa planted alongside cotton to draw away lygnus bugs, or planted in strips alongside tobacco to protect from heliothis
2. chervil protects from slugs
3. Soybeans protects by rye (protects from corn seeding maggots), sesbania (protects from stink bugs), sicklepod (protects from velvet green caterpillars)
4. mustard planted near strawberries protects from lygnus bugs
5. blue hubbard squash planted near cucurbits protect them from squash vine borers and cucumber beetles
Host-finding disruption
Any green ground cover confuses pests which must make a certain number of "appropriate landings" on their host plant before laying eggs. If they make too many inappropriate landings, they leave the area.
eg. clover ground cover
Beneficial "weeds"
1. mimosa pudica - attracts predatory beetles
2. Euphorbia lathyris - repels moles
3. urtica dioica - young leaves are edible and can attract beneficial insects
4.Allium vineale - repels slugs, aphids, carrot fly, and cabbage worms. Can be used as conventional chives. Do not plant with beans, peas, or parsely.
5.Brassicas - attract ladybugs and traps brassica pests including aphids
6. Rosa - deter rodents and deer, and trap Japanese beetles
7. Borago officinalis - attract predatory wasps
8. Taraxacum (dandelion) - attract pollinators and large tap root breaks up soil and transports nutrients from the deep soil to the surface
9. Trifolium (clover) - flowers attract pollinators. Do not plant near tomatoes, which prefer a mild nityrogen deficit in the soil.
10. neem - repels insects
11. blackberry - edible and may deter large mammals, attracts predatory insects
12. burdock - roots, stalks, and young leaves are edible
13. Stellaria media - edible and grows as ground cover
14. Centaurea cyanus - edible
15. Hypochaeris radicata - leaves are edible raw, roots are edible after being roasted
16. Equisetum (horsetail) - tops can be eaten like asparagus
17. Chenopodium berlandieri - leaves and shoots edible raw, prevents erosion, distracts leaf miner pests
18. Portulaca oleracea - edible (raw or sauteed)
19. Capsella bursa-pastoris - leaves are edible
20. Nasturtium officinale - can be eaten raw or cooked, but may contain potentially-fatal liver fluke
21. Leonurus cardiaca - attracts bees
22. Eutrochium - attracts pollinators and predatory insects
23. genus Aster - attract predatory insects
24. Vigna unguiculata (cowpea) - attracts ladybird beetle
25. Solanaceae - breaks up hardpan
Other beneficial plants
1. Artemisia - repels ants, cabbage looper, cabbage maggot, carrot fly, codling moth, flea beetles, whiteflies, the Cabbage White, and the Small White, as well as mice
2. basil - repels flies and mosquitoes, the carrot fly, asparagus beetles and whiteflies
3. borage - repels tomato hornworm and cabbage worms
4. catnip - repels ants, flea beetles, aphids, the Japanese beetle, squash bugs, weevils, the Colorado potato beetle, the cabbage looper, and cockroaches
5. chamomile - repels flying insects
6. chives - repels carrot fly, Japanese beetle and aphids
7. chrysanthemums - repel roaches, ants, the Japanese beetle, ticks, silverfish, lice, fleas, bedbugs, and root-knot nematodes
8. citronella - repels insects and deters cats
9. clover - repels aphids and wireworms
10. Lantana camara - repels mosquitoes
11. coriander - repels aphids, Colorado potato beetle, and spider mites
12. cosmos - repel corn earworm
13. Fritillaria imperialis - repel rabbits, mice, moles, voles and ground squirrels
14. dahlias - repel nematodes
15. dill - repels aphids, squash bugs, spider mites, the cabbage looper, and the Small White
16. eucaluptus - repel aphids, the cabbage looper, and the Colorado potato beetle
17. fennel - repels aphids, slugs, and snails
18. Lantana ukambensis - repels mosquitoes
19. Mirabilis - attracts and kills Japanese beetles
20. garlic - repels root maggots, cabbage looper, Mexican bean beetle, and peach tree borer
21. geraniums - repel leafhoppers, the corn earworm, and the Small White
22. Hyssopus officinalis - repels the cabbage looper and the Small White
23. Delphinium - repels aphids
24. lavender - repels moths, scorpions, water scorpions, fleas, and flies, including mosquitoes
25. leek - repel carrot flies
26. lemongrass - repel mosquitoes
27. Melissa officinalis - repel mosquitoes
28. Thymus citriodorus - repel mosquitoes
29. lettuce - repels carrot fly
30. Ocimum americanum - repels mosquitoes
31. myrrh - repels insects
32. narcissus - repels moles
33. nasturtiums - repel squash bugs, aphids (though there is conflicting information with some sources stating it attracts aphids), many beetles, and the cabbage looper
34. onion - repels rabbits, the cabbage looper, and the Small White
35. oregano - repels many pests
36. parsley - repels asparagus beetles
37. peppermint - repels aphids, cabbage looper, flea beetles, squash bugs, whiteflies, and the Small White
38. petunias - repel aphids, tomato hornworm, asparagus beetles, leafhoppers, and squash bugs
39. carnivorous plants - trap and kill insects
40. radish - repels cabbage maggot and cucumber beetles
41. rosemary - repels cabbage looper, carrot fly, cockroaches and mosquitoes, slugs, snails, as well as the Mexican bean beetle
42. Salvia yangii - repels wasps
43. rue - repels cucumber and flea beetles
44. Sarracenia pitcher plants - particular adept at trapping yellowjackets
45. spearmint - repels fleas, moths, ants, beetles, rodents, aphids, squash bugs, and the cabbage looper
46. Amaranthus spinosus - repels cutworms
47. Collinsonia canadensis - repels mosquitoes
48. Satureja hortensis - repels bean beetles
49. Tanacetum vulgare - repels ants, many beetles and flies, squash bugs, cutworms, Small White, and Cabbage White
50. Thymus vulgaris - repels cabbage looper, cabbage maggot, corn earworm, whiteflies, tomato hornworm, and Small White
51. Nicotiana tabacum - repels carrot fly, flea beetles and worms
52. tomato - repels asparagus beetles
If you have this pest, use...
Ants: Artemisia, catnip, chrysanthemums, spearmint, Tanacetum vulgare
Cabbage Looper: Artemisia, catnip, dill, eucalyptus, garlic, Hyssopus officinalis, nasturtiums, onion, peppermint, rosemary, spearmint, Thymus vulgaris
Cabbage Maggot: Artemisia, radish, Thymus vulgaris
Root maggots: garlic
Carrot fly: Artemsia, basil, chives, lettuce, rosemary, Nicotiana tabacum, leeks
Codling moth: artemisia
Flea beetles: artemisia, catnip, peppermint, rue, Nicotiana tabacum
Whiteflies: Artemisia, basil, peppermint, Thymus vulgaris
Cabbage White: Artemisia, Tanacetum vulgare
Small white: Artemisia, dill, geraniums, Hyssopus officinalis,
onion, peppermint, Tanacetum vulgare, Thymus vulgaris
Mice: Artemisia, Fritillaria imperialis
Flies: basil, lavender, Tanacetum vulgare
Mosquitos: basil, Lantana ukambensis, Lantana camara, lavender, lemongrass, Melissa officinalis, Thymus citriodorus, Ocimum americanum, rosemary, Collinsonia canadensis
Asparagus beetles: basil, parsely, petunias, tomato
Hornworm: borage, petunias, Thymus vulgaris
Aphids: catnip, chives, clover, coriander, dill, eucalyptus, fennel, Delphinium, Nasturtiums (conflicting information), peppermint, petunias, spearmint, marigolds
Japanese beetle: catnip, chives, chrysanthemums, Marabilis
squash bugs: catnip, dill, Nasturtiums, peppermint, petunias, spearmint, Tanacetum vulgare
Weevils: catnip
Potato beetle: catnip, coriander, eucalyptus
Cockroach: rosemary, catnip, chrysanthemums
Ticks: chrysanthemums
Silverfish: chrysanthemums
Nematodes: chrysanthemums, dahlias
Fleas: chrysanthemums, lavender, spearmint
Wireworms: clover
Worms: Nicotiana tabacum
Spider mites: coriander, dill
Corn earworm: cosmos, geranium, Thymus vulgaris
Moths: lavender, spearmint
Scorpions: lavender
Rabbits: Fritillaria imperialis, onion
Slugs & snails: fennel, rosemary
Mexican bean beetle: garlic, rosemary, Satureja hortensis
Peach tree borer: garlic
Leafhoppers: geranium, petunias
Cucumber beetles: radish, rue
Wasps: Salvia yangii, Sarracenia pitcher plants
Cutworms: Amaranthus spinosus, Tanacetum vulgare
.jpg)
cabbage looper
root maggot
carrot fly
codling moth
flea beetle
white fly
cabbage white
small white
asparagus beetle
hornworm
Japanese beetle
squash bug
weevil
potato beetle
silverfish
nematodes
nematode
wireworms
spider mites
corn earworm
Mexican bean beetle
peach tree borer
peach tree borer damage
leafhopper
cucumber beetle
cutworm
Plant Combinations to Avoid
Some plants inhibit the growth of others, either through soil chemical means or by attracting pests. Avoid these combinations.
Alliums (onions, garlic, leeks, shallots, chives): Beans and peas
Asparagus: onion, garlic, potatoes, gladiolus
Bush Beans: fennel, soybeans, dry beans, alfalfa
Pole Beans: sunflowers, beets, brassicas, kohlrabi
Beets: runner or pole beans
Brassicas: mustards, nightshades (tomatoes, peppers), pole beans, strawberries
Cabbage: grapes
Carrots: dill, parsnip, radish
Celery: corn, asters
Corn: tomatoes, celery
Cucumber: potato, aromatic herbs (Lamiaceae - mint family)
Leek: Swiss chard
Legumes: Alliums, gladiolas
Lettuce: celery, cabbage, cress, parsley
Solanums (nightshade family - tomatoes, peppers): beans, black walnuts, corn, fennel, dill, brassicas
Onion: lentils, peas
Peppers: beans, kale (cabbage, Brussels sprouts)
Potato: atriplex, carrot, cucumber, pumpkin, raspberries, squash, sunflower, tomato
Pumpkin: potatoes
Radish: grapes
Tomatoes: black walnut, alfalfa, corn, fennel, peppers, peas, dill, potatoes, beetroot, brassicas, rosemary
Turnips/rutabagas: hedge mustard, knotweed
Apple: cedar, walnut
Apricot: peppers
Blueberries: tomatoes
Grapes: cabbage, garlic, radishes
Passion fruit: cucurbits, maize, cowpea, sorghum, okra, sweet potatoes
Strawberries: brassicas, (Verticilium-susceptible species) tomatoes, potatoes, eggplant, peppers, melons, okra, mint, bush or bramble fruits, stone fruits, chrysanthemums, roses
Basil: common rue, thyme
Caraway: dill
Chervil: radish
Chives: beans, peas
Dill: carrots, tomatoes
Fennel: almost everything
Flax: almost everything
Garlic: cabbage, grapes
Hyssop: radish
Lovage: rhubarb
Parsley: alliums, lettuce
Sage: Alliums, common rue
Geraniums: tomatoes, tobacco, eggplants, other nightshades
Lupin: tomatoes and other nightshades
Nasturtium: cauliflower
Sunflower: pole beans
Alfalfa: tomatoes and beans
Walnut: apple, grasses