Companion plants for onions can be found in different varieties such as flowering plants, vegetables, and fruits. These plants can be grown alongside onions to conserve garden space, maintain soil fertility, and enhance the aesthetic value of your outdoor environment.

20 Companion Plants For Onions

However, it may be challenging to identify suitable companion plants for onions. So, we have made this list to help you out. Have a look at the plants we’ve listed below.

List of Companion Plants for Onions

1. Garlic

Similar to onions, garlic is a part of the Amaryllis group and can be found in almost all vegetation gardens in Asia. Its bulbs are made up of densely compacted cloves that are covered in a papery layer on the outside.


– Growth Requirements

In order to successfully cultivate this plant, you will need to select a spot that receives a lot of full sunlight, and it would have loose, fertile, and well-drained soil. When you plant onions, you can plant garlic in the same bed.

– Highlighted Characteristics

This is an annual, edible, bulb, and cool season vegetable plant with a medium growth rate and contains fragrant green linear leaves. It would be very helpful to drive all the pests away from your garden, because of the natural chemical that it releases.

2. Broccoli

Broccoli is one of the most wonderful onion companion plants. It is a member of the family of Brassicaceae and may be found growing on the stony sea cliffs that line the beaches of Western Europe. It is able to flourish in a diverse range of environmental settings.


– Growth Requirements

It achieves its maximum potential only when grown in a setting that provides constant sunlight, soil that is rich in nitrogen and alkaline, and adequate drainage. Make sure that the soil is not acidic, and it is neutral, meaning the pH scale is 6.8 to 7.0.

– Highlighted Characteristics

It is an edible herb-type plant that grows at a medium rate and contains fleshy blue or green leaves. It is one of the most prominent vegetables that you can grow next to your onion, because they have similar grow requirements.

3. Cabbages

This vegetable is one of the most used vegetables around the world. In addition, it has a natural releasing odor which would keeps pests from laying their eggs and developing their habitat far away from your crops.


– Growth Requirements

The plants in the cabbage family possess hardy leaf plants and thrive in temperatures that are lower, often hovering about 60 degrees Fahrenheit. Temperatures above 75 degrees have the potential to cause bolting, which is when a plant starts to develop too quickly, at which point it stops flowering and sets seeds. The optimal conditions for growth involve exposure to direct sunlight, while prolonged periods of shadow might impede development.

– Highlighted Characteristics

These edible cool-season vegetable plants have a medium growth rate and showy, deciduous leaves with green, lavender, purple, or white color. It is fast growing one, that when given the right conditions, it will grow bigger in its size.

4. Cauliflowers

The Cauliflowers can be an excellent addition to your vegetable garden alongside onions. Spring and fall are the traditional growing seasons for it.


– Growth Requirements

It is best to plant seeds in the springtime for a harvest in the early summer, and then again in the later months of summer for a harvest in the fall. Maintaining moist soil that is high in nitrogen will produce the best crop yields. The application of compost is highly recommended for the purpose of soil enrichment.

– Highlighted Characteristics

It is an annual, edible, cool-season vegetable plant that requires medium maintenance and contains simple, edible, green leaves. They have similar growth requirements to broccoli, however, these would grow in a more wide scope.

5. Carrots

Carrots share a genetic background with a number of other pungent herbs, including fennel, parsley, and dill. They get their orange color from the high beta-carotene content in their flesh, which also makes them an excellent source of vitamin A.


– Growth Requirements

Remember that these are vegetables that rooted ones, which means their nutrients are gotten from the soil, so the roots much be kept in an organic and a cool soil, just like the condition of the onions. On the other hand, the shoots of the onion will be providing shades for the carrots, and on the note of watering, you must water it one inch every week.

– Highlighted Characteristics

It is an edible, annual, cool-season vegetable plant that requires deficient maintenance and contains fragrant, edible, green leaves.

Carrots are technically biennials because they don’t produce flowers until the second year after planting, although they are typically grown and harvested as annuals for consumption. Growing onions and carrots together is an excellent idea due to carrots’ high food value.

6. Strawberries

You can grow onions with Strawberries to have vegetables and fruits at the same time. Strawberries are the result of a chance mating between a species native to North America and one native to Chile. This mating took place in Europe.


– Growth Requirements

When you are growing strawberries, they have similar requirements to that of onions, they get irrigated well as the rain would shower them, and they would bloom together in late winter, early spring. On another note, their soil must be a well draining and a fertile one.

– Highlighted Characteristics

This edible, ground cover-type plant requires very high maintenance and contains green leaves that get yellow, orange, or red color during the fall season. Because of the delicious, ruby-red fruits, they are frequently cultivated in gardens and on commercial farms. They are typically divided into two categories: kinds that bear fruit in June and types that bear fruit year-round.

7. Lettuce

You should not grow only onions all year round but perform a crop rotation to keep your soil healthy for different plants. You can do it by planting lettuce beside onions.


– Highlighted Characteristics

It is a cool-season vegetable plant with a rapid growth rate and contains fleshy, deciduous, edible, and showy leaves. It has been developed to grow in a variety of forms, colors, and textures to accommodate a wide range of growing circumstances, serve a variety of storage functions, and add visual appeal to a dish. It is simple to cultivate at home.

8. Beets

Beets are also known as the Swiss Chard. This species of plant belongs to the family known as Amaranthaceae or the Amaranth, and it is endemic to both the Mediterranean and Europe.


– Growth Requirements

A proper planting guide for Beets would suggest that they thrive in conditions ranging from full sun to moderate shade and in soil that is wet, rich, and well-drained. Even if they are still capable of growing well in part shade, this will take the plant significantly more time to mature to the point where it can be harvested.

– Highlighted Characteristics

This vegetable plant requires low maintenance, has a medium rate of growth, and contains deciduous and edible leaves that have burgundy, red, lavender, purple, or green color.

9. Parsnip

The Parsnip is a good choice if you are looking for good companion plants for onions. It has a long taproot that has skin and flesh that is a creamy color, and if it is allowed to mature in the ground, it has a sweeter flavor after the winter frosts.


– Growth Requirements

You must also remember that these vegetables ones are roots too, just like onions, which means their soils and watering requirements are of the same, they both must grow in an area of moist and a cool soil, that is also organic.

– Highlighted Characteristics

This cool-season vegetable plant has a coarse texture and has an alternate leaf arrangement with gold or yellow color flowers. The parsnip is a vegetable that is native to Eurasia. It has been consumed as a food source from ancient times and was farmed by the Romans.

10. Potatoes

Companion planting onions with potatoes is an excellent idea for your garden. Potatoes have the potential to reach a height of two feet, and their growth can be erect or sprawling, with branching stems. The plant produces stolons, which are followed by underground tubers that can be consumed. The green parts are uneatable because they are loaded with a poison called solanine.


– Highlighted Characteristics

It is an herbaceous perennial vegetable plant that requires medium maintenance and contains elliptical, orbicular, ovate, or oblong-shaped leaves with green color. Potatoes are the fourth most significant crop in terms of food production and are grown for the starchy tubers that they produce.


The Tomato plant is also a great companion for onions. It’s the most common type of vegetable cultivated at home. The fruits are available in a wide range of colors, including yellow, red, and purple, and in sizes ranging from very little to very enormous.


– Growth Requirements

remember that you should grow your tomatoes on a vine, because they must receive proper sun in order to thrive and turn bright red. The tomatoes should be kept in a slightly acidic soil, just like the onion crops you are planting.

– Highlighted Characteristics

This herbaceous perennial is a warm-season vegetable plant with a rapid growth rate, requires medium to high maintenance, and contains fragrant leaves that are cordate, lanceolate, or ovate-shaped. The plants have the potential to reach heights of three to ten feet and widths of one to four feet. In most cases, the plant will have gland hairs that are exceptionally sticky.

12. Eggplant

The reason why it is great to cultivate onions and eggplants in the same place is because they would help each other grow, and they have similar requirements, which means you would care for the both of them in a similar way.


– Growth Requirements

Eggplant is often considered to be one of the ideal plants to grow with onions. It does best when grown in direct sunlight. It grows best on soils that are fertile, sandy, loamy, well-drained, and wet. Flea beetles, Colorado potato bugs, tomato horn worms, and cutworms are all examples of pests that can attack this plant and so pest control is a must for eggplants.

– Highlighted Characteristics

It is an annual, edible, and warm season vegetable plant with a medium rate of growth and it requires medium maintenance and contains prickly green, lavender, or purple color leaves.

13. Summer Savory

The Summer Savory has a long history of use and popularity in Atlantic Canada. It is the primary seasoning in the dressing for many birds. It can reach a height of about one to two feet and has leaves that are quite slender and a bronze-green color. Onions benefit greatly from having this plant nearby as it is a wonderful companion plant.

Summer Savory

– Growth Requirements

In order to grow these herbs, you must keep in mind that almost all pests will be flying away, because the summer savory together with onion crops would release natural aroma that is pest repellent. Overall, they have similar growth requirements, such as a moist and a well-draining soil that is very organic.

In addition, it needs to be placed in a location where it will be provided with full sun on a daily basis, and you may water it once a week, or when you see the soil is not moist enough.

– Highlighted Characteristics

It is an herb and perennial type plant that contains edible leaves and blooms pink or white flowers during summer.

14. Chamomile

The Chamomiles are one of the members of the Asteraceae family, which are also known as the daisy family, and indigenous to Western Asia and Europe.


– Growth Requirements

Because their root systems are creeping and robust, these plants grow and continue to maintain a stable base. When planted, these plants should have about three inches of space around them so that they can reach their full potential. The blossoms make for an excellent companion that may be grown alongside onions.

– Highlighted Characteristics

This herbaceous perennial ground cover-type plant has a rapid growth rate, requires low maintenance, and contains fragrant, long-lasting, green leaves.

15. Dill

Another fantastic onion companion plant is the dill. This combination allows for the plant to produce the most robust stems.


– Growth Requirments

Dill thrives in temperate settings with full sun, good drainage, and slightly acidic soil. Dill seeds should be planted in early spring, about two weeks before the date of the last hard frost. They should be planted about one-fourth of an inch deep because the seeds require light to sprout.

– Highlighted Characteristics

It is an annual herb with a medium growth rate it requires low maintenance and contains edible, fragrant, linear, green leaves.

16. Mints

Choose mint as an onion companion plant if you want a plant that will help renew the onion’s flavor. It is one of the members of the Lamiaceae family. Mint is a fragrant groundcover that is native to Europe.


– Growth Requirements

This tall perennial does best in full sunlight and in soils that are both well-drained and moist. It can reach a height of around two feet in a short amount of time. One thing that is key to growing this herb is that it needs to be very well watered, but not much that will harm the roots, as it will be sitting in water.

– Highlighted Characteristics

This ground cover perennial grows rapidly, requires very high maintenance, and has edible, fragrant, deciduous, green leaves. It is common to find it growing in wet areas as well as around the edges of ponds and lakes where it is found naturally.

17. Parsley

The states of Idaho, California, Oregon, and Nevada are where parsley originally originated. It is most commonly discovered in damp environments including meadows, the banks of streams, and marshes. Nonetheless, it is one of the most visually appealing plants that may be grown alongside onions.


– Highlighted Characteristics

It is an herbaceous perennial and a wildflower that requires low maintenance and has a medium growth rate and its leaves are green and lanceolate or oblong. It has white blooms that look like buttons. In the late summer, this plant is extremely beautiful due to its blossoms. It has upright stems that can grow as tall as six feet high.

18. Roses

You can cultivate roses in your garden if you want to include flowering plants along with onions. Onions go well with roses. Roses come in many shapes and sizes, some of which include vine roses, shrub roses, hybrid tea roses, old garden roses, and English roses.


– Growth Requirements

They prefer full sun, soils that are organically rich and well-drained and can tolerate moderate to high levels of heat. These high-maintenance plants need to be trimmed every year, but the specifics of that trimming vary from variety to variety of roses.

– Highlighted Characteristics

This perennial, shrub and vine-type plant requires very high maintenance, grows at a medium rate, and blooms fragrant white, red, lavender, purple, pink, orange, or yellow flowers during summer.

19. Marigolds

Marigolds are another lovely flowering plant that you can cultivate alongside onions. Marigolds are indigenous to Mexico, where they can be discovered growing wild in pine-oak forests or as garden escapees along the edges of roadways.


– Growth Requirements

This plant can grow in soil that contains clay and is dry, but it does best in soil that is evenly moist and has good drainage. It does best in full sunlight which helps it bloom more profusely, but it does prefer a little bit of afternoon shade. On the other hand, it does not thrive when grown in complete shade.

– Highlighted Characteristics

It is an annual, poisonous, perennial plant with a medium growth rate, requires low maintenance, and blooms white, burgundy, red, orange, yellow, or cream flowers in summer and fall.

20. Pigweeds

The Pigweed is the last plant on our list of onion companion plants. A notch or cleft at the apex of the leaf blade is a distinguishing characteristic of this plant.


– Growth Requirements

These herbs are one of the most drought tolerant vegetation that can be placed. In addition, it needs to be watered every once a while. However, you should note that they wouldn’t thrive when the weather heats up, because they are not tolerant to the heat, as their growth would hinder.

– Highlighted Characteristics

This annual, herb and weed-type plant bloom flowers during the fall and summer seasons that have white color and it contain ovate or obovate-shaped green leaves. It would appear that the pigweed population is growing at an alarming rate in the Southeast region of the planet.

Furthermore, it is gathered in certain communities so that it can be prepared as a leaf vegetable by cooking. Other uses include medicinal treatments for conditions including boils, abscesses, and inflammations.


There are a lot of companion plants for onions as you have seen in this list and there are different kinds too. To sum up the plants we have mentioned,

  • If you want to cultivate more veggies in your yard, you should harvest potatoes, tomatoes, carrots, and other plants with onions as companions.
  • You can make your garden more beautiful by growing flowering plants as companions for onions, such as roses or marigolds.
  • If you feel the need to grow fruits alongside onions in your garden, strawberry is an excellent choice for the plant to use.

You will profit in either case, regardless of whether you opt for flowering plants or add more vegetables and fruits to your yard that include onions.

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