Just like you and me, plants have preferences. There are some people we love and others we’d like to stay as far away as possible. For greenery, it’s the same. But it’s not like plants can choose, so we have to choose for them.
If you want your garden to buzz and flourish without setbacks, knowing how to pair your greenies is an important step. Some plants will help and boost each other, while others will compete and even damage one another.
Today we’re presenting you with a list of the best onion companion plants, so you’ll know how to have happy plants and achieve a successful harvest.
Best Companion Plants for Onions
First, you have to keep in mind that there are different types of onions. Overall, the majority of onions companion plants presented will work well with all the varieties of this fragrant vegetable. Although most of them have similar companion preferences, there is a slight difference.
It’s important to choose plants that complement one another, and onions are one of the most compatible crops you can find.
Also known as Welsh onion or Spring Onion, this vegetable does not develop bulbs and is often grown as an ornamental plant.
Marigolds (Calendula officinalis)
These beautiful flowers are often a staple in many crop gardens due to their visual appeal and benefits. They keep onions safe since these flowers can prevent nematodes in the soil.
Tomatoes (Solanum lycopersicum)
Planting onions next to your tomatoes will protect them since the pungent odor of onions keeps insects and pests away.
Similarly to tomatoes, planting onions next to any type of melon will protect them from various pests that like to munch on the fruit and its leaves.
Sometimes also referred to as brown onion, it has a strong flavor due to the higher sulfur content.
The cabbage family is considered one of the best options, as they have similar care requirements and soil conditions. Onions will even guard them against pests.
Chamomile (Matricaria chamomilla L.)
Chamomiles and onions make one of the best companions. While onions repel several pests, chamomiles help onions grow and enhance flavor. These flowers also protect onions from root rot and other diseases.
Dill (Anethum graveolens)
Dill, as well as a few other herbs, can protect your bulb vegetable by reducing the population of beetles and aphids that enjoy feasting on the plant's sap. This herb can also have a positive impact on your onions' flavor.
Also known as scallions, it has a milder taste. Green onion bulbs don’t develop fully. They are often sought after for hollow leaves.
Carrot (Daucus carota var. sativus)
This root vegetable is a great companion as it keeps onion flies away. Onions, at the same time, protect orange roots against carrot flies.
Lettuce (Lactuca sativa)
Lettuce grows fast and densely, which benefits the onions by suppressing weed growth. More than that, it's easy to harvest without damaging the surrounding crops, so you can easily remove lettuce leaves to make space for onion bulbs.
Beets (Beta vulgaris)
Beets won’t do anything special for your onions, but they’re still great companion plants. Additionally, onions will protect beets from insects, pests, rabbits, and deer.
Egyptian Walking Onion
More commonly known as the tree onion, this hybrid allium is similar to the common onion but grows in a cluster of bulbs instead of flowers.
Strawberries (Fragaria × ananassa)
Strawberries benefit from various veggie companions, as their foliage protects red fruits from birds. As for onions, the pungent smell of bulbs keeps insects and terrestrial pests at bay.
Parsley (Petroselinum crispum)
Onions enjoy being paired with parsley because this herb can keep some onion pests away, mainly onion flies.
Much like parsley, Mint is also great at deterring insects and protecting veggie bulbs from onion flies. The only downside is that Mint tends to be an aggressive propagator.
These bulbous herbs are characterized mainly by their strong garlicky or oniony scent, although they aren't used for culinary purposes like many others in their genus.
You can grow almost any kind of allium around these flowers. They will often serve as a decoy for insects, feeding on this flower instead of other plants.
The onion scent will effectively deter many insects that munch on your roses. These veggies mask the rose scent and confuse the pests.
Also known as Lady’s Leek, this member of the genus is a wild variety of edible allium. Lady’s Leek is known for exuding the characteristic garlic and onion scent.
Since the nodding onion has some beautiful flowers, it’s only fair to pair it with more beautiful flowers. The big advantage of asters is they attract much-needed pollinators and repel many pests.
This flowering weed will not bring any trouble or work into your garden. Much like asters, this plant is great for properly feeding pollinators, assuring your garden is buzzing with a good kind of insect life.
What Not to Plant With Onions - Bad Companions
Now that you know what to plant with onions, it’s also important to know which plants you should avoid mixing with your smelly bulbs.
As said before, pairing the wrong plants together can lead to several issues, as the greenies will compete for nutrients and stunt each other’s growth, alter their taste, or even increase the risk of pests and disease.
Peas, beans, and other legumes will negatively impact onions, suppressing their growth or even stunting it.
Much like legumes, Sage should not be grown near your onions, as this herb tends to stunt onion growth, making them bad companion plants for onions.
This may surprise you, but plants in the Allium genus shouldn’t be paired with onions. Although they will not get in the way of one another, and caring would be easy due to similar needs, there is a higher tendency for pests, diseases, and infections, mostly of onion maggots.
Asparagus (Asparagus officinalis)
Asparagus will not affect your onions, but your onions will alter this veggie's flavor and stunt their growth, so keep them as far apart as possible.
What Grows Well With Onions?
Generally, the best pick to grow with the majority of onion species is the Cabbage family, from Broccoli to Brussels. Another great option is Chamomile, as this flower enhances the onion's flavor and boosts its growth.
Are Onions Companion Plants for Garlic?
Although they would get along due to similar care needs, you shouldn’t mix any alliums with one another. The reason is that the risk of infestation by genus-specific pests like onion maggots and flies dangerously increases, putting your crops at risk.
What Are the Best Companion Flowers for Onions?
If you’re going for a mixed garden with not only veggies but also lots of beautiful flowers, and you’re wondering what to plant next to onions, try Marigolds or Roses, as these plants tend to get along great with one another.