I have some family in Tennessee and they have wild blackberries growing everywhere. They say the berries are growing fairly well, but they wanted to know what companion plants work best for blackberries. So, to help them out, I did some research. Here’s what I found.
The best companion plants for blackberry plants are blueberries, strawberries, fruit trees, wildflowers, and the allium family. Ideally, companion plants have mutual benefits such as increasing pollination, pest resistance, groundwater, and nitrogen. For best results, avoid planting blackberries with raspberries.
So, while these are some of the best companion plants for blackberries, what benefits do they bring, and what are some other examples of blackberry companion plants? Let’s take a closer look.
Companion Planting Pro Tips (Before You Start)
Companion planting is selecting specific plants to place together for benefits such as increasing pollination or controlling pests. Sometimes these benefits are one-sided, while others are mutual.
A famous example is The Three Sisters—planting corn, beans, and squash together. The corn provides a trellis for the beans to climb, the squash provides a ground cover, and the beans fix nitrogen in the soil. Plus, all of them provide food!
Here’s how to get the most from companion planting:
- Find your USDA hardiness zone
- Select plants that do well in your zone
- Choose the plants that fit each niche or layer in the graphic above (canopy, understory, herb layer, etc.)
- Plant support species first to establish a microclimate and build the soil. For example, before planting fruit trees, grow nitrogen-fixing trees, shrubs, and flowers. Plant one nitrogen fixer for each productive plant (such as fruit trees or berry bushes).
Now, let’s take a look at the best companion plants, their benefits, and other tips to place them in your garden.
1. Blueberries
Blueberry bushes are one of the best choices for companion planting with blackberries. Blueberries mainly benefit blackberry plants by attracting pollinators and beneficial insects (ladybugs, beneficial wasps, and the like).
Since blackberries are a bramble and blueberries are a bush, they don’t compete.
Additionally, blackberries and blueberries both love acidic soil. Blackberries prefer a soil pH between 5.5 to 6.5 (source), while blueberry plants prefer 4.5 to 5.5 (source).
So, to make both berry plants happy, aim for a soil pH of around 5.5.
2. Fruit and Nut Trees
Fruit trees and nut trees make a great over or midstory for blackberry plants, meaning they provide partial shade in times of hot weather, as well as leaf mulch for temperature regulation, reduced evaporation, and fertilizer.
The fruit tree’s roots also break up compact soils and hold groundwater, and their flowers attract pollinators who visit blackberry plants too.
In return, blackberries provide fruit trees with an understory layer, reducing even more evaporation and promoting healthy soil.
Since fruit trees, nut trees, and blackberries are all perennials, you can just plant them once and let them grow and fruit. As long as you have rich, moist soil (and the proper climate) these plants will thrive.
There are many overlapping companions between blackberries and fruit trees. For some more examples, check out my other post on fruit tree companion plants.
3. Strawberries
Strawberry plants are one of the best companion plants for blackberries because they both require a similar acidic pH. According to Oregon State University, strawberry plants require a soil pH of 5.4 to 6.5 (source).
Two good ways to measure soil pH are with pH strips or a pH meter. I prefer using a pH meter since they’re affordable and easy to use. To see which pH meter I use and recommend, check out my recommended tools page.
Strawberries also provide blackberry plants with benefits such as increased pollination and ground cover. As a result, more of the blackberry’s flowers can be successfully fertilized (leading to more fruit) and its soil has greatly reduced evaporation from the living ground cover.
Also, consider planting blackberry and strawberry plants with borage.
For example, a recent study showed that borage interplanted with strawberries saw an increase in strawberry production, with 35% more fruits and 32% more yield by weight.
Other companions for strawberry plants include asparagus, sage, and thyme. Avoid planting strawberries with mint, cabbage, and melons.
4. Hyssop
Hyssop is an evergreen flowering shrub that is often used in herbal remedies. This shrub is fairly hardy in most climates, growing in USDA hardiness zones 3-11 (source), which is a nice overlap with the climate for blackberries.
Many gardeners mention that hyssop is a great companion plant for blackberries as it improves pollination and yields in berry patches.
Closely related to hyssop, mint is another companion plant for blackberries (more on mint later).
Along with your blackberry bushes, hyssop also works great with alliums (more on alliums later too).
5. Tansy
Tansy is a perennial flowering herb that’s native to Europe and parts of Asia. This temperate plant grows in slightly acidic soils ranging from 4.8 to 7.5. Since blackberries prefer a soil pH of 5.5 to 6.5, they have quite a bit of overlap in acidic soil.
Like most flowering plants, tansies are great at attracting pollinators, which can increase the fruit yield of blackberries and their other companions, as well as minimize fruit drop.
Along with blackberries, interplant tansy with legumes, brassicas, cucumbers, squash, corn, and roses.
When planting, be aware that tansy can become invasive, so consider growing it in pots to discourage it from rapidly spreading in the garden.
6. Wildflowers
So, what exactly are wildflowers?
Wildflowers are defined as any flower that has not been genetically manipulated (source).
They include:
- Daisies
- Poppies
- Bee Balm
- Queen Anne’s Lace
- Purple Coneflower
- Meadow Cranesbill
- Lupine
- Black-Eyed Susan
Wildflowers are an amazing addition to your garden, especially if they’re within range of your blackberry plants. Ideally, this is around 25 feet or closer, but no more than 50 feet away as it maximizes the chances pollinators will visit both the wildflowers as well as your blackberry’s flowers.
These varieties of wildflowers are especially appealing to pollinators and provide a good mix of nectar and pollen they can use as sugar and protein.
Wildflowers also attract beneficial insect predators such as birds, ladybugs, and beneficial wasps, which naturally keep pest populations down.
Any of the above wildflowers will work great as a companion plant for just about any fruit, vegetable, or herb plant. However, this isn’t an exhaustive list, so feel free to explore other wildflower varieties!
To see more companion flowers, check out my other post: The Top 10 Companion Flowers for Gardens, Vegetables, & More.
7. Alliums
Garlic, onions, and chives are all part of the same family (allium) and, no surprise—they’re more potent-smelling than most plants. More specifically, this is likely due to their naturally occurring sulfur, which is great at repelling pests as well as its use as a natural anti-bacterial and fungicide.
In fact, these plants’ scents are so effective that some deterrents are even made from garlic (source).
For pests, plant garlic, chives, and onions near your blackberry plants to help repel aphids, mites, maggots, as well as rabbits and deer (source). This is because their pungent sulfur smell and taste are not appealing to these pests’ strong senses.
It’s believed that the sulfur from these plants also helps prevent certain plant diseases to some extent. For example, a common companion plant pairing is interplanting chives near apple trees to prevent apple scab (source).
However, if fungal or bacterial diseases do take hold, garlic cloves can also be mixed into organic sprays along with neem oil and applied as a treatment.
Garlic, chives, and onion plants also have shallow roots that typically don’t exceed 12-18″, making them a good companion to plant outside of the blackberry’s canopy.
These three plants all do well in both full sun and partial sun. However, if you’re in a warmer climate, consider planting them on the east side of your blackberries—so the bush helps shade it from the hot, afternoon west sun.
Overall, you can plant any of these allium-family plants with just about any other plant, except for legumes.
For more pest-repelling companion plants, visit my other post: 7 Companion Plants That Repel Pests
8. Mint
Mint is a perennial native to North America and has many popular uses from mojitos to essential oils. This plant does best in full sun but tolerates partial shade.
It grows by sending runners along the top of the soil and if left on its own, mint grows vigorously and can take over parts of the garden. For this reason, many gardeners prefer to keep mint’s runners at bay by keeping the plant in a pot.
When mint flowers, it’s great at attracting pollinators. Varieties such as peppermint normally get their flowers from mid-summer until fall.
According to the Franklin Park Conservatory and Botanical Gardens in Columbus, Ohio, mint is also used in gardens where its strong scent repels pests such as aphids, ants, cabbage moths, and mice (source).
We have found that placing peppermint cuttings (fresh or dried) where mice are a problem is very effective in driving them off!
Franklin Park Conservatory and Botanical Gardens
For best results, plant mint alongside blackberries and other companions including alliums, beets, cabbage, lettuce, and nightshade fruits (such as tomatoes, potatoes, eggplant, and peppers).
Since mint grows with runners, the same as strawberries, it shouldn’t be a surprise that it should not be planted near strawberries as they can compete. Additionally, they’re known to expose strawberries to the common fungal disease Verticillium wilt (source).
9. Thyme
Thyme is native to Eurasia, with a history dating back to 2750 BC—noting that thyme was dried and mixed with pears, figs, and water for a topical medical paste (source). It’s also a great drought-tolerant plant.
Like just about all of the flowers on this list, thyme’s flowers and scent are incredibly useful at attracting pollinators, specifically honey bees, which directly increases blackberry yields. You can expect thyme to flower from May to September.
Thyme is also resistant to pests including cabbage worms, weevils, and cabbage loopers (source). It’s also said that thyme also reduces aphid populations by attracting ladybugs (an aphid predator).
Of course, thyme has a lot of other uses. At our home, we often use thyme in our bone broths and roasts. We’ve come to really appreciate thyme’s strong floral scent and taste, giving our dishes much more flavor.
Along with blackberries, thyme is best planted with strawberries, brassicas (broccoli, cabbage, cauliflower, etc), rosemary, and lavender. Avoid planting thyme near basil.
10. Cover Crops
Many legumes such as clover, peas, and runner beans (along with some grasses) are also called cover crops as they are great pioneer plants for depleted soils.
Cover crops are used to improve soil health by slowing erosion, retaining water, preventing weeds, and controlling pests and diseases. They’ve even been shown to increase crop yields.
In the drought of 2012, corn and soybean farmers reported a 9.6-11.6% yield increase when they used cover crops, likely due in part to the cover crop’s ability to add 50-150 pounds of nitrogen per acre.
Source
These cover crops fix nitrogen in the soil by promoting beneficial bacteria which take nitrogen from the air and store it in the soil as nitrates for other plants to use (source). This is incredibly valuable for blackberry plants as they require quite a bit of nitrogen to grow properly.
As many cover crops produce a lot of biomass, they can also be used to mulch blackberry plants for even more nitrogen and other nutrients (as well as reducing evaporation).
With cover crops such as clover, you can even grow them in-between your fruit and berry patches and run livestock through the alleys. Your livestock gets free food, many pests are deterred, and your blackberries get an amazing fertilizer in the form of manure.
What Not To Plant With Blackberries
Generally, avoid planting similar brambles with blackberries as they can compete. This especially includes raspberries. Two or more plants within the same niche will compete for sunlight, water, and nutrients, which can lead to growth issues.
Other than that, there’s not much that you can’t plant with blackberries. Remember, there are more plant companions out there than there are foes, so don’t be afraid to experiment with different plants!
