Friendly Companion Plants for Onions
The following are compatible companion plants for your onions. Onions repel many of the insects that invade these plants.
- Lettuce – Lettuce has shallow roots, so it doesn’t interfere with the growth of onion bulbs.
- Carrots and Beets – Rabbits do not eat onions and the odor repels them, so your root vegetables have time to mature.
- Cabbage – Onions repel the insects that attack members of the cabbage family. These insects include cabbage loopers and cabbage worms.
- Tomatoes – Onions deter Japanese beetles that feast on tomato leaves.
- Strawberries – Onions repel aphids, which invade strawberry leaves.
- Chamomile and summer savory – Planting chamomile near your onions improves the onions’ flavor, and the scent makes it harder for insects to find the other plants in your garden. These herbs also improve the flavor and growth of onions.
- Pigweed and sow thistle – These raise beneficial nutrients from the soil that help onions grow, improving their health.
Incompatible Companion Plants for Onions
Not all plants grown in a garden are compatible. Some give off toxins that can cause chemical imbalances in other plants, stunting growth or causing flavor changes.
Avoid planting peas, beans, asparagus and sage with your onions. Onion family plants prevent beans and peas from growing to their full size. These plants can cause a chemical imbalance that is detrimental to the flavor of the onions.
Planting other members of the onion family, such as chives, leeks, garlic and shallots near onions is not a good idea. All of these plants attract onion maggots. The more onion-type plants you put in your garden, the more onion maggots will invade your crop.
Planting Onions with Companion Plants
When planting your onion seedlings with companion plants, intersperse them between the other plants you choose. This way the onions will deter insects from invading your other plants. Using this organic method to repel insects is safer that applying pesticides to your garden plants.