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Jason's Field Notes

Companion Planting Guide

techniques
Zone 3-11 spring

How Companion Planting Works

Companion plants serve three roles: attracting pollinators, luring pests away (trap crops), and repelling pests with scent. Here are the best companions, especially for brassica-heavy gardens.

Pollinator Attractors

Borage

Attracts beneficial insects like bees and other pollinators. Plant near any crop that needs pollination.

Yarrow

Attracts pollinating butterflies, parasitoid wasps (which prey on caterpillars and aphids), hoverflies, ladybugs, and lacewings.

Dill

Allow dill to bolt and bloom to attract beneficial insects. The flowers draw pollinating bees, butterflies, hoverflies, ladybugs, lacewings, and parasitoid wasps that destroy brassica caterpillars and aphids.

Trap Crops

Marigolds

Attract pollinating bees. They lure pests like aphids and soilborne nematodes away from your vegetables — an excellent trap crop.

Nasturtium

The foliage appeals to aphids, flea beetles, and whiteflies, drawing them away from your main crops.

True Hyssop

Attracts pests that feed on cauliflower — brassica caterpillars, flea beetles, and slugs — pulling them away from your food crops.

Peppermint

Attracts brassica caterpillars, flea beetles, and nematodes as a trap crop. Also repels aphids and cabbage moths with its strong scent.

Pest Repellents

Geraniums

Repel cabbage worms, cabbage loopers, and flea beetles with their peppery, astringent scent. Also attract aphids away from Brussels sprouts. Plant alongside nasturtiums for maximum effect.

Quick Reference

PlantAttracts BeneficialsTrap Crop ForRepels
BorageBees, pollinators
YarrowButterflies, wasps, ladybugs
Dill (blooming)Bees, wasps, hoverflies
MarigoldsBeesAphids, nematodes
NasturtiumAphids, flea beetles, whiteflies
True HyssopCaterpillars, flea beetles, slugs
PeppermintCaterpillars, flea beetlesAphids, cabbage moths
GeraniumsAphidsCabbage worms, loopers