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Onions are nature’s bug repellent when it comes to gardening. They can help keep bugs out of your garden. Some of the many pests that they help keep out of the garden are Japanese beetles, cabbage loopers, cabbage worms, aphids, rabbits, and many more. This is why using onions for companion planting is a great idea in a home garden. In this article, we go over companion plants for onions and what not to plant with onions.
Good Companion Plants for Onions
- Brussels Sprouts
Broccoli, Brussels Sprouts, Cabbage, Kohlrabi, and Kale all benefit from having onions as a companion plant due to the onion repelling common Brassica family pests like cabbage worms, cabbage maggots, and cabbage loopers.
Beets help amplify the pest repelling abilities of onions. When used as a companion plant beets help deter aphids, rabbits, and deer.
Carrots benefit from onion’s ability to help keep the carrot fly away from your growing carrots when used as a companion plant.
Chamomile can help improve the flavor of onions planted nearby.
Garlic is a companion plant for onions with limits. You can plant these two together to help with insect repelling, but you do run the risk of making it easy for onion maggots to travel from plant to plant when they are planted together. So if you do use garlic as a companion plant make sure to divide your crop so you don’t lose all your onions and garlic if by chance you do get onion maggots.
Kohlrabi is a good companion with onions because onions can help deter harmful insects away from the area.
Marigolds make a great companion crop for many herbs and vegetables in the garden, and onions are one of those too. Marigolds can help bring in pollinators to the garden and also can help boost insect repelling.
Radishes, when used as a companion crop for onions, should be used as a trap crop. Radishes help attract root maggots to themselves, and when using this as a trap crop should be thrown out after you harvest your onions.
Rhubarb benefits from onions as a companion crop because onions are able to help keep weevils and leaf beetles away. Find other crops you can plant with rhubarb here.
Strawberries can a good companion plant for onions because strawberry plants are very susceptible to pests. Onions can help keep away aphids, which tend to love strawberry crops.
Tomatoes are a good companion crop for onions, as they benefit from the insect repelling ability of onions.
What Not To Plant With Onions
Beans and Peas don’t do well as a companion plant with onions, as they affect the onion’s ability to thrive.
Parsley can have its growth affected if planted near onions.
Pumpkins have a shallow root system and harvesting onions that are planted near them could damage that root system.
Asparagus, Potatoes, and Sage both will have their growth stunted if used as companion plants with onions.
Find Other Companion Plants for These Crops:
- Companion Plants for Asparagus
- Companion Crops for Green Beans
- Companion Crops for Parsley
- Companion Plants for Peas
- Companion Plants for Potatoes
- Companion Plants for Pumpkins
- Companion Plants for Sage
Frequently Asked Questions About Companion Planting for Onions
Yes, tomatoes and onions can be planted together. Tomatoes benefit greatly from onions helping keep pests like aphids away.
Onions grow best with the herbs dill, garlic, and chamomile.