How to Grow Onions: Onion Companion Planting Guide

Onions make great planting companions due to their ability to improve the flavor of their companion plants, as well as deter pests like aphids, Japanese beetles, and rabbits. However peas, pole beans, bush beans, and asparagus don’t grow well when planted near onions. It’s important to know which crops make good companions with others in order to attract beneficial insects and produce the highest quality harvest.

1. 1. Cabbage. Onions will generally work best with Brassicas, members of the cabbage family. Onions are great at repelling insect pests like cabbage worms, cabbage loopers, and cabbage maggots. Broccoli, kale, cauliflower, turnips, kohlrabi, and brussels sprouts are all Brassica vegetables that fare well when planted next to onions, as the onions keep away most of the pests that plague cabbage crops.
2. 2. Chamomile. Along with its antibacterial and antifungal properties, chamomile improves the flavor of onions when planted in proximity.
3. 3. Summer savory. Savory can help encourage the growth of your onions as well as helping make them slightly sweeter.
4. 4. Carrots. Onions can help repel the dreaded carrot fly. By surrounding your carrot crop with onions, you can keep the garden pest from destroying your carrot harvest.
5. 5. Leeks. While some same-family plants may not work well together, the onion family (also known as alliums) can. Onions and leeks make a good pair due to their similar environmental needs—both require similar nutrients, and leeks are effective at confusing onion flies.
6. 6. Beets. Beets benefit from an onion companion plant. Along with leeks and garlic, onions can be a natural deterrent for certain garden pests, providing protection from insect pests like aphids and sugar beet-flea beetles, as well as mammal pests, like rabbits and deer. Learn how to grow beets in your home garden here.
7. 7. Lettuce. Onion has a shorter root depth than lettuce, so these two crops can be planted next to one another without competing for resources, allowing you to maximize the planting space in your vegetable garden.
8. 8. Strawberries. Strawberries are an extremely vulnerable crop to pests. They’re a favorite of aphids, and can be hard to keep free from disease and destruction. Onions help protect the strawberry crop, which can improve the health of your harvest.
9. 9. Tomatoes. The onion’s pungent odor is a great repellent that protects your tomato plants.
10. 10. Swiss chard. The large leaves of the swiss chard can help keep the ground soil moist, providing a ripe environment for the short-rooted onion to grow. Swiss chard can be planted near most members of the allium family (like shallots and chives) for a mutually beneficial relationship.
11. 11. Marigolds. These pungent flowers are useful for attracting beneficial insects that can pollinate, as well as feed on the various pests that may harass your garden.

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