Garden pests can be repelled naturally
Crop rotation is not planting the same crop (green beans), crop family (soybeans) or similar crop (peas) in the same spot as last year because the soil nutrients needed for this year were depleted by last year’s planting. In addition, you’ll avoid soil borne diseases and pests that congregated and ate that crop last year.
Companion planting is growing two or more different types of plants together that like and/or enhance each other. Interplanting is growing different crops at the same time in the same space. Trap crops are sacrificial plants so the intruder will stay away from the crop you really want to harvest, and a good example is zinnias distracting Japanese beetles. Biodiversity is a blending of interplanting, companion planting and trap crops on a grander scale by planting a wide variety. Unwanted insects are confused by something they will not touch being planted around something they love to munch.
Remove troublesome insects via sprays, handpicking, trapping, barriers or introducing beneficial insects. What to spray on plants depends on which insect is attacking. If it is a chewing or biting insect like caterpillars, cutworms or grasshoppers, garlic, onion and pepper sprays may work. Sucking insects such as aphids, squash bug nymphs and flies are asphyxiated by soap solutions. Trap slugs under damp boards or with a saucer of beer. Earwigs can be trapped in dark places such as an upside down container full of shredded paper. Barrier examples: tar paper collars around brassicas for cutworms or white maggots and Vaseline for ants. Consult an insect book to make sure what is on your plant is an unwelcome guest before picking them off. Sometimes an insect is unwanted or beneficial depending on the stage of growth.Yarrow, lavender, bee balm and the aster, carrot, onion and mint families attract beneficial insects that’ll make meals of the pesky ones.
Following is a list of plants and sprays that chase off unwanted insects.
Ants do not like pennyroyal, spearmint, or tansy. Catmint, garlic, nasturtium, nicotiana, artemisia family, spearmint, stinging nettle, soap or garlic spray will take care or aphids and pot marigold will ward off the asparagus beetle.
Plant mint or wormwood to guard against black flea beetle, and black horehound or stinging nettle for black flies.
Cabbage worm moths do not like anise hyssop, mint, rosemary, sage, thyme or Artemisia and Carrot rust flies do not like sage. The Colorado potato beetle will be kept at by with catmint, eggplant, flax or green beans while radish, nasturtium, zinnia and aster are plants that the cucumber beetle does not like.
Rue or tansy will keep flies away. Datura, grapes, white roses and white geranium are some plants that Japanese beetles don’t like. The Mexican bean beetle will avoid potatoes, and mosquitoes don’t hang around legumes.
Lavender, mint, sage and stinging nettles deter moths. Potato bugs avoid eggplant and flax.
If you sprinkle your plants and surrounding soil with dried and ground hot peppers, root maggots will leave them alone.
Diatomaceous earth or lime keeps slugs and snails away from susceptible plants.
Squash bugs don’t like catmint, nasturtium or tansy spray, while borage and dill guard against tomato cutworm/hornworm.
Weevils won’t eat garlic. Perhaps they don’t like the smell.
None of these are foolproof, but they do make your gardening against pests easier.
Part II of repelling garden pests naturally will cover deer, rabbits, raccoons, and rodents.
Aideen Vega-Van Auken is a Master Gardener.