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If you want to save money on your grocery bill and enjoy more vibrant green smoothies, scrumptious kale salads, or crunchy kale chips, growing your own organic kale is crazy simple.
Kale is one of the trendiest, most popular superfoods at farmer’s markets and grocery stores for good reason: it’s nutrient-dense, flavorful, and has a versatile texture that lends well to a wide variety of recipes. In the garden, kale grows quickly and can yield massive plants with frilly, curly leaves or crumpled “dinosaur” textures.
But, like all Brassicas (cabbage-family crops), most varieties of kale are prone to a few issues. Aphids, flea beetles, and cabbage worms (from those white butterflies you see flying around the garden) are a few annoying pests that can put a serious dent in your kale harvest.
Thankfully, the age-old wisdom of companion planting offers a simple way to protect your kale from pests while beautifying your garden and enjoying extra yields. Here’s everything you need to know about the best companion plants for kale.
A Brief Overview of Companion Planting
Companion planting is an ecological growing method for planting multiple species in the same space to aid in each other’s growth. Flowers, herbs, and vegetables can work together to create symbiotic relationships that promote higher yields, less pest pressures, and/or other ecosystem benefits.
Because it adds biodiversity to a growing space, companion planting is a key way to maximize the resilience of your garden while simultaneously getting the most out of a small space.
Different companions have different functions, including:
- Repelling pests with fragrant leaves or floral aromas.
- Attracting beneficial predators (that eat pests).
- Attracting pollinators.
- Utilizing bare ground.
- Creating layers to the garden canopy (to maximize space).
- Fixing nitrogen.
- Making more soil minerals available to crops.
- Out-competing weeds.
- Loosening the soil profile.
But the most popular reason for companion planting is to reduce the need for pesticides or organic sprays. In this sense, companion planting is technically called conservation biocontrol.
Biocontrol means using living organisms (insects, animals, or presets) to prevent or reduce damage from harmful organisms (pests, common weeds, or disease-causing pathogens). For example, releasing ladybugs to reduce aphid damage, or using chickens and ducks to eat slugs.
Conservation biocontrol is specifically using “built-in” biocontrol species rather than purchasing or importanting predators. For example, planting a flower that attracts predatory insects to the garden and creates long-term habitat for those beneficial bugs.
All scientific jargon aside, this is a simple ancient practice. You mimic a wild ecosystem wherein hungry predators like lions keep fast-multiplying herbivores like rabbits in check. The same processes happen on a micro-scale with flies, wasps, and beetles that keep aphids, flies, fleas, and slugs under control.
Essentially, by companion planting, you are transforming your garden into a self-sustaining ecosystem that doesn’t depend so much on you for pest control.
Benefits of Companion Planting with Kale
Kale is a member of the Brassicaceae family, sometimes called Brassicas or cole crops. Like its cousins cabbage, brussel sprouts, and broccoli, some pesky bugs are notoriously hungry for these vegetables.
Anybody who has dealt with aphid-infested kale knows how unappetizing our favorite supergreen becomes when its leaves are covered in nasty sap-sucking bugs. But nobody wants to spray toxic pesticides or constantly wipe neem oil all over the garden.
Interestingly, companion plants are scientifically-proven to reduce aphid pressure and increase species richness in kale plantings. This happens because certain species either:
- Attract predators that eat aphids.
- Repel aphids with their strong smell.
- Create more diversity (rather than a monoculture).
Depending on the companions you choose, you can reap all of these benefits in a single kale planting. Sometimes a combination of companion plants is even better for creating more ecosystem services and diversifying your harvests.
Best Companions to Plant With Kale
Kale is a vigorous cool-season crop native to Europe. In many regions of the United States, it can be grown year-round, however hot weather often poses more pest and disease issues for this brassica.
Companion plants can help kale throughout the season by reducing pest pressure, preventing diseases, improving nutrient absorption, and keeping weeds in check. Just don’t forget to plant companions at the proper time and spacing to allow both plants to thrive.
Let’s dig into the details and functions of each kale companion and how to plant them:
Sweet Alyssum
As the hallmark of companion plants, white or sweet alyssum (Lobularia maritima) benefits just about every vegetable in your garden. It attracts loads of beneficial predatory insects like lacewings and parasitic wasps as well as vital pollinators like bees and butterflies. Moreover, it smells like sweet honey and blooms lovely little white flowers all spring, summer, and fall.
Benefits
Attract predatory insects to control pests, including:
- Lacewings
- Parasitic wasps
- Hoverflies
- Ladybugs or lady beetles
Ladybugs in particular can eat up to 50 aphids per day as adults, and over 300 aphids as developing larvae. They love hanging out in the scrumptious nectar-rich growth of alyssum plantings.
How to Plant It
Thanks to alyssum’s low-growing habit, it can be tucked into any kale bed without much issue. I prefer to plant it at every row end of the four corners of a raised bed. It won’t compete with kale for light or nutrients, and it may even help with weed suppression as it grows into a low-spreading bush. Start your alyssum indoors early so you can get it into the spring garden as soon as possible.
African Marigold
Marigolds are another companion plant classic that can be grown with a range of garden vegetables. The pest-repellent properties of marigolds are well-researched and can be useful for keeping both above-ground and soil-dwelling pests at bay.
While Mexican (also known as African) Marigolds (Tagetes erecta) are lovely, they can grow up to 6 feet tall. French Marigolds (Tagetes patula) are far better suited to companion planting.
Benefits
Repel aphids, root knot nematodes, and potentially rabbits
Studies have shown that marigolds intercropped with kale drastically reduce aphid populations by attracting parasitic wasps and predatory syrphid flies. They also happen to add beautiful pops of color into dark green kale plantings.
How to Plant It
First, be sure that you have French Marigolds that stay around 1 foot tall. Any color will do for attracting predators.
Also pay attention to the timing of this companion duo. Since it takes French Marigolds up to 100 days to flower, fall kale is often sown or transplanted into a bed that already has marigolds in it at the end of the summer. Plant 3-4 marigold plants along the perimeter of the kale bed or alternated throughout the row, providing at least 8-12” from the nearest kale plant.
Calendula
A lesser known flower, Calendula officinalis is often used in herbalism and as a pest repellant. It is often mistakenly called “pot marigold”, so be sure to check the seed or plant label.
Its resinous blossoms have a strong scent that magnetizes beneficial inects. The flowers are also a deligtful edible garnish and make great ornamental plants.
Benefits
Attract beneficial predator insects like hoeverflies, lacewings, and ladybugs to control a variety of pests, inlcuding:
- Aphids
- Thrips
- Nematodes
We also love that calendula continuously produces flowers. Pick off the withered blossoms and watch them bounce back with more.
How to Plant It
Calendula enjoys blooming in cool spring weather. You can seed it in the spring after the danger of frost has passed. It takes 6-8 weeks (42-56 days) to flower from the time of seeding, so it’s ready to defend kale from the get-go. Tuck calendula into kale rows, at row ends, or along the margins of brassica beds. Make sure calendula plants have 10-12” of space from each kale plant.
Cilantro/Coriander
Though its renowned as a summer salsa ingredient, cilantro absolutely loves the cool weather of spring and fall when we most commonly grow kale. The leaves alone are fragrant enough to repel pests, but the real benefits come in summer and fall when cilantro sends up lacey umbel flowers and coriander seed heads. Beneficial predators are magnetized to the blossoms in particular.
Benefits
Scent repels pests and flowers attract beneficial insects, including parasitoid wasps to control aphid populations
How to Plant It
If you seed cilantro at the same time as kale, you can enjoy a few harvests of the herbal leaves before the plant bolts in the warmer weather. Then, leave the flowers for the beneficial bugs to enjoy (hopefully leading to some handy aphid control). Cilantro is best planted 10-12” from its kale neighbors, but can be 2-6” apart from nearby cilantro. I like to sow a row of cilantro between each row of kale in the spring.
Dill
Can you see the theme with umbel-shaped blossoms? Beneficial predatory insects go crazy for dill flowers and you also get the flavorful bonus of dill leaves and seeds for summer pickling. Many gardeners have anecdotal reports of young dill enhancing the vigor of nearby newly transplanted vegetables.
Benefits
Enhance kale growth and attract predatory insects
How to Plant It
Start dill inside and plant in the garden after danger of frost has passed or direct seed dill outdoors in the garden at any time during the summer. Try to plant dill 8-12” from young kale to help protect the new transplants. Feel free to harvest a few side leaves and then let the plant flower and seed to get the maximum companion benefits.
Lemongrass
A popular herb used in Thai and Chinese food, lemongrass has multiple uses. Though it’s a tender tropical perennial in zones 9-10, it can be grown as an annual in cooler zones 5-8. As a companion, its citrusy aroma keeps aphids, flea beetles, and other hungry pests at bay.
It is a relatively light feeding herb, so you don’t have to worry about competition with your kale for nutrients.
Benefits
Deters and distracts pests
Lemongrass conceals the smell of kale that many pests use to find the crop. It also adds a delicious extra harvest to the garden that can be very competitve with weeds.
How to Plant It
Lemongrass grows up to 3 feet wide and tall, so be sure to give it plenty of space from your kale plants. It’s best to keep it in a separate nearby bed or only along the corners of a raised bed.
Bush beans
Bush beans are easy-going legumes that rev up kale growth by making nutrients more available to your crop. Kale can use up a lot of nitrogen throughout its long growing season, however the use of synthetic nitrogen fertilizer has been linked to outbreaks of pests. This is because the spikes in nitrogen levels from quick-release fertilizers leads to rapid multiplication of aphids and mites who thrive off the sap inside plant leaves.
Research shows that slow-release organic fertilizers like legumes, compost, or manure result in fewer infestations of aphids. This is precisely why bush beans are so beneficial to kale. They use Earth’s natural cycles to make nutrients available to kale.
Benefits
Enhance kale growth through nitrogen fixation.
Due to the beans’ leguminous nature, they can form a symbiosis with a special bacteria that “fixes” atmospheric nitrogen and transforms it into plant food for your kale.
It’s like a triple symbiosis: you get free fertilizer, pest control, and more food all-in-one! How’s that for a self-sustaining garden ecosystem?
How to Plant It
Bush beans can be grown quite close to each other, but need at least 10-12” from the nearest kale plant. They can also be used as a companion before the kale planting; sow beans in early summer, harvest for a few months, then remove the plants and plant kale in their place. There will be leftover nitrogen in the soil to fuel your fall kale succession. Just be sure that you lop off bean plants at the base and leave their roots in the soil to keep feeding the kale.
Hot peppers
Spicy peppers (Capsicum species like cayenne, Thai chilis, jalapenos, and habaneros) are a nice compliment to kale’s mild nature. A strong-smelling substance in hot peppers called capsaicin deters insect pests as well as hungry animals in the garden. Peppers are also nice because they won’t compete with kale for nutrients.
Benefits
Maximize bed harvest and deter insects, deer, and rabbits.
You can harvest the peppers for kitchen use or you can save a few to make homemade hot pepper sprays to help pest problems on other plants. Wear gloves to harvest a spicy pepper like habanero, blend a single paper with a bit of water until liquified, then dilute in a spray bottle to kill off aphids, flea beetles, or leafhoppers.
How to Plant It
I like to alternate kale plants with pepper plants within a row, leaving 12-18” between each.
Scallions
Allium-family companions are always a pleasure in the garden. Scallions (green onions), in particular, are fast growing and easy to tuck into young kale beds. Their scent and oils repel flea beetles, cabbage loopers, and aphids. Because they don’t take up much space, they also have the added benefit of giving you an extra harvestable crop from your kale bed.
Benefits
Repel pests and maximize small space gardens.
Scallions are delicate and thin enough to not compete with kale for light or nutrients. They also mature very quickly.
How to Plant It
Scallions can be grown from transplants or onion sets. Tuck them in alongside newly planted kale for protection from pests, and they will be ready to harvest before the kale overtakes them. Space at 2-3” from each other and 4-6” from the kale row.
Onions
Onions aren’t as easy to tuck alongside kale as scallions, however they have a much stronger smell as they mature. Intercropping with onions has been scientifically-proven to repel insects in brassica plantings. Studies show that planting onions between kale or cabbage rows provides the most repellant benefits.
Benefits
Deter pests and loosen soil.
The sulfurous compounds in onions release an odor both above and below ground to keep pests away from them as well as their kale neighbors. An added benefit is their bulbous nature that tends to create more air pockets in the soil.
How to Plant It
Onions can be transplanted at the same time as kale in spring or fall. They need 10-12” of space from the kale plants and ideally can sandwich your kale rows or be planted around the whole margin of a raised bed to deter hungry leaf-feeding insects.
Leeks
Long-season leeks are one of the best cold-hardy winter pals for kale. The pungent onion-y smell of leeks acts like a natural insecticide and pest repellant for kale aphids and flea beetles. The bulky base and root zone of leeks is also great for aerating the soil to promote better drainage, which may aid in preventing brassica diseases like black rot.
Benefits
Repels pests and loosen soil.
Because kale grows sweeter after frost, it is the perfect companion for leeks both in the garden and in the kitchen. There is also no risk of leeks crowding or competing with your kale, as long as they are properly spaced apart.
How to Plant It
Leeks take from 90 up to 150 days to mature, so they need to be started in early spring before kale. Once transplanted at 2-6” apart between leeks, you can plant kale 12-16” from the leek row. Leeks will hold in the ground long into the frosty fall while kale leaves sweeten and curl.
Garlic
This iconic allium probably has the most benefits as a kale companion because of its seasonality and extremely strong smell. Garlic is one of the most popular pest deterrents as a companion plant and as a spray (prepared like the pepper spray described above). Best of all, it spends a lot of its life underground, meaning you can maximize your harvest in a small area.
Benefits
Repel pests and maximize harvestable space.
How to Plant It
Garlic is typically planted in the fall and harvested in the summer, meaning it has an extended cold dormant period during the season that kale loves most. Plant garlic bulbs in rows between fall kale, leaving 6” between cloves and the baby kale plants.
Then, mulch over the garlic and around the base of the kale for added insulation and weed control. As the kale grows and sweetens above ground, garlic will be establishing roots and preparing for spring below ground. You maximize your space and get extra pest protection throughout fall and spring (if overwintering your kale).
Cucumbers
Some companions are best for keeping weeds at bay while kale grows and adding another harvestable fruit to the equation. Cucumbers can ramble and vine under taller kale plants during the warm season with the bonus benefit of keeping the soil cool for summer kale plantings.
Benefits
Weed-suppressing ground cover and keep the soil cool.
This companion planting can be a bit more tricky to pull off if your kale isn’t tall enough or your cucumber plants get too out of control. Monitor closely to make sure they aren’t competing.
How to Plant It
Choose a vining cucumber variety and direct sow or transplant into the late spring garden after the danger of frost has passed. Your kale can be already established or transplanted at the same time. Only plant one cucumber every 2-4 kale plants to allow plenty of space for the vines to ramble.
You may need to adjust their direction so they don’t override your kale plants. A straw mulch can also be beneficial to both crops by helping keep the cucumbers out of the soil and keeping the kale cool in the summer.
Nasturtiums
Nasturtiums are a different type of kale companion because they actually attract caterpillars, aphids, and flea beetles. How could that be beneficial, you may ask? Well, they act as a bit of a sacrifice or “trap crop”.
Essentially, garden pests are drawn to the lily-pad leaves of nasturtiums. The fast growing flower can easily withstand them and keep them away from your kale. At the same time, the pests eating the nasturtiums provide food to fuel insect predator populations.
Benefits
Trap crop.
How to Plant It
Plant nasturtiums outside of kale beds at least 6 feet away. This companion planting likely only works when other beneficial-attracting plants are nearby. Be sure that you have ample populations of ladybugs and other predators that can feed on the pests that eat the nasturtiums. This can help maintain predator populations in case they are needed to control outbreaks in your kale. Optionally, you can remove and destroy the nasturtiums to get rid of the pests.
Radish
Though it’s typically not recommended to plant brassicas together, I give radishes a free pass. Radishes mature in under 30 days and are so easy to tuck alongside young growing kale. Radishes are lowkey and unlikely to compete with kale for water or nutrients.
Benefits
Maximize small space harvest.
How to Plant It
Direct sow radishes 4-6” from the base of newly transplanted baby kale plants. By the time the kale leaves mature and overtake the row, the radishes will be ready to pull out and enjoy.
What Not To Plant With Kale
Kale is pretty friendly with most plants in the garden, but a few of them are best kept at a distance:
- Too many other brassicas: it’s best to rotate brassica family crops.
- Sunflowers: they can prevent kale germination.
- Tomatoes: large canopy can shade out or take nutrients from kale.
- Strawberries: attract kale pests and rodents.
Final Thoughts
The biggest problems with kale are undeniably aphids and flea beetles. The bulk of companion plants either repel these annoying pests or attract the predators we need to eat them. At the same time, dill and legumes can enhance the growth of kale to make it more vigorous and resilient. Cucumbers can even be used to vine underneath taller kale plants and keep them cool in the summer.
Ultimately, companion planting is as much of a science as an art. It can take a bit of experimentation to get your companion plantings just right, so don’t get discouraged if a pairing gets a little out of whack. At the end of the day, any addition of biodiversity into the garden is always going to be a good thing.
