Companion Planting With Onions – Learn About Onion Plant Companions

onion companions
onion companions
(Image credit: peplow)

Companion planting is maybe the easiest organic way to encourage health and growth in your garden. Simply by placing certain plants next to others, you can naturally repel pests and stimulate growth. Onions are especially good companions to certain plants because of their ability to deter bugs. Keep reading to learn more about companion planting with onions.

What Can I Plant with Onions?

Far and away the best onion plant companions are members of the cabbage family, such as:

This is because onions naturally repel pests that love cabbage family plants, like cabbage loopers, cabbage worms, and cabbage maggots. Onions also naturally deter aphids, Japanese beetles, and rabbits, meaning that good companion plants for onions are any plants that often fall victim to them. Some other particularly good onion plant companions are:

Bad Companion Plants for Onions

While onions are mostly good neighbors across the board, there are a couple of plants that should be kept away from them because of chemical incompatibility and possible flavor contamination. All varieties of peas and beans can be detrimental to onions. The same goes for sage and asparagus. Another bad onion neighbor is actually other onion plants. Onions frequently suffer from onion maggots, which can travel easily from plant to plant when they’re spaced close together. Other onion-like plants, such as garlic, leeks, and shallots, are common targets of onion maggots as well. Avoid planting them near onions so the onion maggots can’t travel easily. Scatter your onions throughout the garden to prevent the spread of onion maggots and to benefit as many other plants as possible with the onions’ presence.

Liz Baessler
Senior Editor

The only child of a horticulturist and an English teacher, Liz Baessler was destined to become a gardening editor. She has been with Gardening Know how since 2015, and a Senior Editor since 2020. She holds a BA in English from Brandeis University and an MA in English from the University of Geneva, Switzerland. After years of gardening in containers and community garden plots, she finally has a backyard of her own, which she is systematically filling with vegetables and flowers.