Onion Companion Plants: 16 of the Best Plants to Grow With Onions

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A gem in your garden is onions. They enhance the flavor of other crops by forming good friendships with them. They also deter pests from attacking your plants. Onions are a great choice for companion planting this year.

Onions are a money crop that is simple to establish. Onions are extremely useful in the kitchen, so planting as many as you can fit in your garden is a no-brainer.

Let’s look at what to plant alongside them and a few to avoid if you want to make the most of your onion crop by embracing companion planting.

Best Companion Plants for Onions

Onions thrive in full sun and don’t like being overshadowed by other plants. The pH should be between 6 and 7, with drainage that is excellent. Onions will rot in damp soil. Temperatures of 55 to 75 degrees Fahrenheit are ideal for them.

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The best plants to share space with onions are listed below.

1. Carrots

Carrots (Daucus carota subsp. carota) are improved by onions. Because they help to repel carrot fly, they are called sativus. Surround your carrot patch with onions if you have one. The carrot fly hates the smell of onions, so the onions serve as a barrier to it.

You might also choose between carrots and onions in alternate rows.

2. Beets

Since onions are a powerful pest repellant, it makes sense to surround them with insect-prone crops like beets (Beta vulgaris), which need care. Because of the sulfur-like odor they release, some aphids and sugar beet beetles don’t like onions.

Plant a lot of onions around your beet leaves if you have trouble with rabbits, hares, and deer eating them. I place the beet seeds in the middle of the planting area, surround them with a series of different onion rows.

When you need to get to the beets, just make sure you can.

3. Swiss Chard

Beta vulgaris subsp. Beta vulgaris is a type of Swiss chard. To help keep the soil moist, vulgaris) can provide shade to the ground. Chard would not obstruct sunlight from reaching the onions since it does not grow too huge. The onions will be harmed if there is too much shade.

Onions prefer moist (but not wet) soil because they are short-rooted. The use of swiss chard as a companion plant helps.

Between the onion rows, plant Swiss chard, but keep it at least 12 inches away from the nearest onions. If the garden faces the afternoon sun, you could plant the swiss chard behind the onions.

4. Leeks

Due to the pests and diseases they may attract, it’s often a good idea not to plant similar plants from the same family together. The heavenly duo of leeks and onions is a surefire winner. Their soils are comparable, as are their temperature and nutrient needs.

For onions, leeks are an effective weapon. The onion fly is perplexed by the leek odor when it comes after the onions. Next to them, plant alternate rows of leeks and onions, or leek and onion alternating rows.

5. Summer Savory

Certain companion plants aren’t beneficial, but instead enhance the quality and quantity of the produce. Onions become slightly sweeter and grow larger when grown in the summer savory (Satureja hortensis).

Summer savory may reach a height of two feet, so be careful about the shade. Place onions in the sunlight facing outward. Saturate the soil with water, but don’t overdo it.

6. Brassicas

The whole family of Brassica genus benefits from being companion planted with onions. These include:

  • Cabbage
  • Cauliflower
  • Broccoli
  • Kale
  • Kohlrabi
  • Mustard

Planting turnips near onions is a bad idea. Turnip flavor can be influenced by them.

Pestsilipps are ubiquitous, but onions may help protect Brassica. Several of the insects attracted to brassicas are repelled by the odor of onions. Spraying and treating can be saved in a big way by this.

7. Lettuce

In comparison to onions, lettuce (Lactuca sativa) grows quickly. When the onions are still tiny, sow the lettuce seeds. After that, you can harvest the lettuce and let the onion bulbs develop on their own.

Several pests that infest lettuce, such as slugs, snails, and aphids, will be repelled by onions.

8. Strawberries

Since you may assume the onions will impact the strawberry’s sweet flavor (Fragaria x ananassa), this isn’t a frequent combination. Onions will repel many strawberry pests, but this isn’t the case.

On the edges of the onion patch, plant strawberry rows that are about 12 inches apart from one another.

9. Chamomile

Chamomile (Matricaria recutita and Anthemis nobilis) improves the flavor of onions when it is cultivated close together, not only making it a excellent plant for herbal remedies and teas, but also improving their taste.

When placed in an onion garden, Chamomile appears to thrive. In addition, chamomile’s antifungal properties may aid onions resist fungal diseases when the weather is humid.

10. Peppers (Hot and Sweet)

Many of the pests that like pepper plants are repelled by onions, protecting them. Young pepper plants attract aphids and cutworms, but onions repel them. Within 12 to 18 inches of onion rows, plant pepper.

11. Melons

Onions are used to repel pests that are drawn to melons. Melon aphids and spider mites are two examples of these. As long as the melon vine isn’t protruding straight through the onion rows, most melons benefit from being planted with onions. The onions will most likely be smothered by their fruit and suffocated by light and moisture. Melons are a good option to try:

  • Honeydew
  • Watermelon
  • Cantaloupe

12. Radish

Radishes (Raphanus raphanistrum subsp. raphanistrum) Everyone in the garden is friends with Sativus. They grow quickly and may be sown in almost anyplace, including among onions.

Plant radishes between onion rows, as well as between individual onions within the row.

With this companion planting combination, there is no clear advantage to either onions or radishes, although both harvests are suitable. Before you even consider harvesting the onions, radishes have grown quickly and are long gone.

You might even sow two radish seeds, but make sure to leave the onion bulbs alone.

13. Parsnips

Onions help Parsnips (Pastinaca sativa) as much as carrots do. Because of the onion scent, they readily share space. The onions repel the same pests that carrots suffer, but parsnips suffer them as well.

On one side is a row of onions, and on the other is a row of parsnips. It operates effectively.

14. Dill

Dill (Anethum graveolens) and onions can coexist peacefully. Dill, like onions, enhances the flavor of onions and is a useful herb in the kitchen.

15. Borage

Borage attracts wasps that hunt for many of the pests that harm crops, including as onions, and attracts them to the garden.

This little-known herb will also help keep your companion herbs in the garden safe. Both cabbage and tomato worms are repelled by borage.

16. Marigolds

Marigolds (Tagetes spp.) are effective for growing between the onions in the rows, and they are well known for repelling aphids. Marigolds may be placed around the onion rows to keep pests at bay, or along the garden’s boundaries.

17. Mint

Mint confusingly emits a powerful odor that attracts insects, particularly onion flies.

I suggest you plant mint in pots that you can remove at the conclusion of the growing season because it will take over the garden wherever it is planted.

Mint will also help tomatoes grow alongside onions, so it’s a good idea to put the mint pots between both crops while you’re planting them. Make sure that the mint roots don’t spread through the bottom of the pots and into the earth.

4 Plants to Avoid Putting With Onions

Onions don’t like everything. Four types of plants to avoid are listed below.

1. Legumes

Onions and beans should not be eaten together. Onions emit a chemical that inhibits the growth of beneficial bacteria on beans’ roots. This might stunt the plant’s development or even kill it.

Other legumes that don’t get along with onions, such as:

  • Peas
  • Lentils
  • Alfalfa
  • Clover
  • Chickpeas
  • Soybeans
  • Lupins

Planting onions after you have legumes in an area of the garden helps to fix the soil with nitrogen. Nitrogen feeders, onions are one of them.

2. Sage

Onions don’t benefit from sage, but the circumstances it demands are unique. The onions will suffer if you try to provide the sage with the perfect conditions, and the same goes for the sage if you try to provide it with suitable growing conditions.

The best approach is to keep the two plants as far apart as possible.

3. Asparagus

Unless you are constantly in the garden monitoring them, onions and asparagus compete for the same nutrients, so one will suffer if not both.

It takes a long time for asparagus to grow and develop year after year. Harvesting the onions near to the asparagus will disturb them.

4. Other Alliums (Except Leek)

Onions should be kept at a distance from garlic and shallots. You’ll lose all three crops if you move onion maggots from onions to garlic or shallots.

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