Yarrow (Achillea millefolium) is a perennial flower that’s equally at home in meadows as it is in cut flower gardens. I love that yarrow provides beautiful lacy foliage and flowers and a wide variety of uses and benefits.
First, yarrow’s tiny flowers attract and feed various insects and birds. Many of these critters are fantastic to have in your garden since they pollinate flowers and/or eat pests.
Second, yarrow flowers have an elegant yet understated beauty that works in both rustic and modern bouquets. And if you’re not interested in cutting the flowers indoors, you can still enjoy their beauty in the garden.
Finally, yarrow offers numerous medical uses. People have used various parts of the plant to ease pain from toothaches and throat infections, lessen the impacts of head colds, and smooth skin.
Since yarrow offers so many benefits, it’s no surprise that it can be a welcome addition to your garden! We’re going to cover some of the best companion plants for yarrow as well as a few plants you should avoid planting next to this perennial.
You can learn more about companion planting here.
While I’ve introduced a few of the reasons I love yarrow above, let’s dive a bit further into why you should add this plant to your garden. What benefits does it provide to other plants?
With the proper care, yarrow will produce flowers from mid-spring through mid-fall. And that means it’s a great source of nectar and pollen.
Many insects rely on pollen and/or nectar for food. Some of these insects include hoverflies, parasitic wasps, butterflies, tachinid flies, green lacewings, lady beetles, and predatory mites.
While the adults of these insects may follow a primarily vegetarian diet, the larvae feed on some types of common garden pests. For example, green lacewing larvae eat aphids, thrips, and whiteflies, and tachinid fly larvae feed on pests such as cabbage worms and armyworms.
If these beneficial insects are around to eat pests, these pests are less likely to get out of control. This means your plants can stay healthy, and you can avoid applying insecticides or excluding pests with row covers.
Since yarrow is a perennial plant that provides dense foliage, it also provides places where beneficial insects can hide.
When mature, yarrow plants can reach about three feet in height. This means that it can be a natural source of shade for heat-sensitive plants.
Placing plants like lettuce and spinach on the eastern side of yarrow plants can help protect the greens from the harsh afternoon sun.
In general, the best companion plants for yarrow fall into two main categories.
First, there are other perennial meadow plants that have similar care requirements as yarrow. Combining these plants can create a low-maintenance garden or landscape that adds both beauty and ecosystem services.
Second, there are edible plants that benefit from yarrow’s ability to attract and support beneficial insects. When you plant yarrow next to these plants, you can help keep potentially detrimental pests in check.
1. Black-Eyed Susan
The black-eyed Susan, also known by its genus name Rudbeckia, is another type of flowering perennial that is native to much of the United States. It has similar ideal habitats as yarrow, which makes these two plants a natural pairing.
Both yarrow and black-eyed Susan can survive in a variety of soil conditions as long as the soil is well-draining. Since both plants require full sun and are drought tolerant, you can provide similar care for each.
Finally, both of these flowers produce continuous blooms as long as you deadhead old flowers. Placing the plants next to each other will allow you to easily complete this task for both species.
2. Purple Coneflower
Purple coneflower, aka Echinacea purpurea, is another native wildflower that fits in well with yarrow. Both plants grow to similar heights, which means that neither shades out the other.
Both of these perennial plants also require full sun and well-draining soil, which means you can plant them in the same area of your garden or landscape.
These plants are also a great pairing because they provide slightly different benefits to wildlife. While both provide pollen and nectar to insects, the coneflowers’ larger seeds attract birds like goldfinches and chickadees.
While some people say that yarrow can choke out coneflowers, I’ve found these two plants can exist together nicely. The key is to provide enough spacing between plants so both can flourish.
One more native perennial plant that is a great yarrow companion plant is coreopsis, also known as tickseed. This genus of plants consists of long, thin stems that are topped with delicate flowers.
Both coreopsis and yarrow can grow in relatively poor soil and also survive periods of drought. And since they don’t like being waterlogged, you can get away with watering these plants just once a week during the summer.
Remember how we said yarrow can help keep pests from eating common garden vegetables? Well, broccoli is one plant that can benefit from yarrow’s ability to attract beneficial insects.
As a brassica, broccoli is susceptible to attack from a wide variety of pests. These include tiny critters like flea beetles and aphids as well as larger insects like cabbage worms and harlequin bugs.
Planting yarrow near broccoli can help attract predatory insects like parasitic wasps, green lacewings, and tachinid flies. When the adults of these good bugs are in your garden, they often choose to lay their eggs near problem pests. After the eggs hatch, the larvae feed on the pest.
Since broccoli can get quite large, plant it at least two feet away from your yarrow plant. This will give both plants space to grow as well as access to plenty of sun.
Cabbage is another type of brassica that often experiences an onslaught of pests. If you step away from your plants for a week, you may return to see them munched on by armyworms, cabbage worms, and cabbage loopers.
Since these caterpillars can quickly devour a cabbage plant’s tender leaves, quickly controlling the pests is key. However, that often means scouting the plants for pests every few days.
If you’d like to think less about looking for and controlling these pests, you can opt to plant a diverse garden that is attractive to beneficial insects. Yarrow’s flowers provide food for caterpillar enemies like parasitic wasps and tachinid flies.
When the adult forms of these natural enemies are in your garden, their larval forms are more likely to attack these common cabbage pests. Oftentimes, that means healthier cabbage plants, less work, and fewer pesticides!
You got it, another brassica! Cauliflower is another vegetable crop that is a delicious food source for pests like cabbage worms, flea beetles, aphids, and harlequin bugs.
If you plant yarrow in your garden, natural enemies of these pests are more likely to call the area home. And that means it’s more likely that these beneficial insects will help keep pest populations in check!
Plant cauliflower at least two feet away from yarrow plants. However, you may still receive the benefits of yarrow even if you plant it ten or twenty feet away from cauliflower.
Arugula is susceptible to attack from many of the same pests that feed on larger brassicas. I’ve seen it devoured by flea beetles and yellow-margined leaf beetles, amongst others.
Since arugula is often harvested as a baby green, a little bit of damage from insects can affect a serious portion of each plant. And since you eat the greens rather than a flower head, insect holes can make the crop unsightly.
Covering arugula with insect netting or row cover is one way to exclude pests. However, this can cause issues when condensation and rot.
Another option is to rely on natural predators like parasitic wasps and green lacewings. Planting yarrow with your arugula can help attract beneficial insects and keep pest populations low.
Rosemary and yarrow are both drought-tolerant perennials, which makes them great companions. You can plant them in a drier area of your yard and watch them both thrive.
Since both of these plants are perennials, you’ll want to think about their full size before you add them to your garden. While you can dig them up and move them after planting, getting the spacing right on the first try is a better option.
Yarrow can grow up to three feet tall and three feet wide while rosemary can grow up to five feet tall and five feet wide. That means you should space the plants a least three to four feet apart, even if they’re quite small when you plant them.
As mentioned above, yarrow grows three feet tall. This means you can use it to shade heat-sensitive crops like lettuce.
While lettuce likes at least six hours of sun, it can become stressed by harsh afternoon light. Planting lettuce on the east side of yarrow plants can help provide shade and cool the plant.
If you want to utilize the shading abilities of yarrow, plant your lettuces about one foot away from the yarrow.
Lettuce also has a relatively shallow root system, while yarrow’s roots run deep. That means yarrow can help reach nutrients that lettuce cannot.
Yarrow’s flowers can also help attract beneficial insects like green lacewings and ladybugs that feed on pests like aphids and thrips.
Tomatoes can also fall susceptible to small and large pests. Tiny sap-sucking pests like aphids, thrips, and whiteflies can weaken plants and spread disease, while larger pests like tomato hornworms and stink bugs can eat or damage both foliage and fruit.
It’s true that tomato plants produce flowers, but these flowers generally don’t provide much food for beneficial insects. Plus, tomatoes don’t begin producing flowers until they are at least a month old.
Planting yarrow in the same area as your tomato plants can help attract predatory insects that feed on tomato pests.
While many plants can benefit from yarrow’s ability to attract beneficial insects, not every plant is a great companion for yarrow. If possible, avoid planting these plants near your yarrow.
Ginger isn’t the most commonly grown crop, but more and more gardeners are experimenting
with growing this tropical herb. As a tropical plant, ginger thrives with lots of heat and moisture.
Yarrow, on the other hand, likes its soil on the drier side. Unfortunately, it can develop fungal diseases like powdery mildew if grown in moist areas.
Since ginger and yarrow prefer such different environments, it’s best to avoid planting them together. You can plant them in the same garden, but you will need to provide each plant with different amounts of water.
Since yarrow plants often develop powdery mildew, you should avoid planting cucumbers near these perennials. Cucumbers are susceptible to powdery mildew, and this disease can quickly destroy the plants.
Cucumbers also grow in a sprawling manner. That means they can climb over yarrow plants and overwhelm them.
Additionally, since yarrow can grow up to three feet tall, it can shade out cucumber plants. This can cause the plants to become stunted and also increases the odds they will develop fungal diseases.
However, it’s important to note that yarrow can attract predatory insects that can feed on cucumber pests like cucumber beetles and aphids. However, placing yarrow plants more than ten feet away from cucumbers will help attract these insects without harming your cucumber plants.
3. Winter Squash
Winter squash varieties like butternut and delicata are also susceptible to developing powdery mildew. Therefore, if yarrow plants develop powdery mildew, the disease will likely spread to the squash plants.
Many winter squash plants also develop vines that can grow over ten feet long. These vines may take over yarrow plants.
Yarrow is a powerful plant that can provide many benefits to the garden and home. It can attract predatory insects, add beautiful flowers, and help provide shade.
Properly designing your garden can help you get the most out of yarrow’s beneficial characteristics.