Blackberry Companion Plants

Planting the right neighbors for your brambles can make a huge difference in your harvest. Choosing the best blackberry companion plants is a simple way to support a healthier, more productive garden with less work from you.

This approach, called companion planting, uses natural relationships between plants. Some plants attract good insects, others improve the soil, and a few can even help keep pests away. For blackberries, smart companions mean better berries, fewer diseases, and a garden that feels more balanced.

Let’s look at how to select plants that will help your blackberries thrive.

Companion planting works by creating a mini-ecosystem. Instead of a row of just blackberries, you create a community where each plant plays a role. The goal is to mimic nature, where diversity creates strength.

For blackberries, the main benefits of companions include:

Pest Management: Certain plants repel common blackberry pests like Japanese beetles or raspberry crown borers.
Pollination Boost: Flowers attract bees and other pollinators, which your blackberries need for fruit set.
Soil Health: Deep-rooted plants can bring up nutrients, while others add nitrogen back into the soil.
Weed Suppression: Low-growing plants act as a living mulch, shading out weeds.
Space Efficiency: You can grow more food in the same area by using vertical and ground-level space wisely.

Understanding Your Blackberries Needs

Before picking companions, know what your blackberries require. They are perennial plants with deep roots. They love full sun and well-drained soil that is slightly acidic.

They also need good air circulation to prevent fungal diseases. So your companion plants shouldn’t crowd them or create too much damp, still air around the canes. Keeping this in mind is key to success.

What to Avoid Planting Near Blackberries

Some plants are bad neighbors. They might compete too aggressively for water and nutrients or share diseases and pests.

Generally, avoid planting these near your blackberry patch:

Other Brambles: Raspberries, boysenberries, and dewberries can share diseases like verticillium wilt and anthracnose. Keep them separate.
Nightshades: Tomatoes, potatoes, eggplants, and peppers are susceptible to similar soil-borne diseases.
Certain Trees: Walnut trees release juglone, a substance that can inhibit the growth of blackberries.

Top Companion Plants for Blackberries

Here are some of the most effective and reliable plants to grow alongside your blackberries. These choices are based on traditional gardening knowledge and proven results.

1. Herbs for Pest Repellent and Pollination

Herbs are fantastic companions. Their strong scents confuse and repel many insect pests. Plus, when they flower, they are a magnet for beneficial insects.

Chives & Garlic: Their pungent smell deters aphids and Japanese beetles. Plant them around the border of your patch.
Tansy: This is a powerful repellent for ants, Japanese beetles, and other crawling pests. Be aware it can be invasive, so contain it in a pot.
Bee Balm (Monarda): As the name suggests, it brings in bees and other pollinators from miles around. It also has a nice scent.
Hyssop: Attracts pollinators and repels cabbage moths. Its tall, spiky flowers add nice structure.

2. Flowers for a Healthy Ecosystem

Flowers aren’t just pretty. They are working hard to protect your berries. They bring in predator insects that eat common pests.

Marigolds: A classic companion plant. Their roots release a substance that helps repel nematodes in the soil. French marigolds are particularly effective.
Nasturtiums: These act as a “trap crop,” attracting aphids away from your blackberries. They’re also edible, with a peppery flavor.
Calendula: Attracts hoverflies and ladybugs, whose larvae consume aphids. It’s easy to grow from seed.
Sunflowers: Provide a tall, sturdy stake for blackberry canes to lean on in a pinch. They also attract birds that may eat pest insects.

3. Vegetables for Ground Cover and Soil

Some vegetables make excellent use of the space under and around blackberry canes. They help keep weeds down and can improve soil conditions.

Beans & Peas (Legumes): These plants fix nitrogen from the air into the soil, providing a natural fertilizer for your hungry blackberries. Bush varieties are best.
Leafy Greens: Lettuce, spinach, and Swiss chard enjoy the dappled shade under blackberry canes in the heat of summer. They have shallow roots that don’t compete too much.
Onions & Leeks: Their strong scent provides a general pest deterrent. They take up little space and are easy to tuck in around the base.

How to Plant Your Blackberry Companions

Planning is essential. You don’t want to damage the blackberry roots or make harvesting difficult. Follow these steps for a successful planting.

Step 1: Prepare the Area

Start with a weed-free zone around your blackberries. Add a layer of compost to the soil to give all the plants a good start. Make sure your blackberries are already well-established, at least in their second year, before planting companions directly around them.

Step 2: Design Your Layout

Think in layers. Tall plants go behind or to the north side of the patch. Low-growing plants go in front or underneath. Leave a clear path for you to access the berries for pruning and picking.

A simple layout might look like this:

Back/North Edge: Tall sunflowers or hyssop.
Around Canes: Chives, garlic, or onions planted in a ring about 12 inches from the base.
Ground Level: Nasturtiums or lettuce spreading between the rows.

Step 3: Planting and Spacing

When planting companions, be careful not to dig too deeply near the blackberry roots. Use a hand trowel for small herbs and flowers.

Maintain at least 12-18 inches of clear space around the crown of each blackberry plant. This prevents competition and allows for air flow. Water everything well after planting.

Maintaining Your Companion Planted Patch

A little ongoing care keeps the system working. The good news is, a diverse planting often needs less intervention.

Watering and Mulching

Water deeply at the base of plants, avoiding overhead watering which can promote fungal disease on blackberry leaves. A layer of organic mulch like straw or wood chips helps retain moisture and suppress weeds for all the plants.

Pruning and Harvesting

Keep up with your blackberry pruning. Remove old fruiting canes after harvest to make room for new growth and to let more light reach your ground-level companions. Harvest your companion plants regularly too—picking herbs and greens encourages more growth.

Seasonal Considerations

In autumn, after the blackberries are done, you can plant a cover crop like clover in the bare spaces. It will protect the soil over winter and add nitrogen in the spring when you turn it in. Some hardy herbs, like chives, will come back year after year on their own.

Troubleshooting Common Issues

Even with companions, problems can arise. Here’s how to handle a couple common scenarios.

If Companions Are Overcrowding: Don’t be afraid to thin or trim back aggressive plants. Nasturtiums and bee balm can spread quickly. The health of your blackberries is the top priority.

If Pests Persist: Identify the specific pest. Companion planting is a preventive strategy, not always a complete cure. You may need to handpick beetles or use an organic spray like neem oil as a targeted solution.

If Blackberries Aren’t Thriving: Check soil pH. Blackberries prefer a pH of 5.5-6.5. If companions are competing too heavily for nutrients, side-dress your blackberries with compost in early spring.

Creating a Long-Term Perennial Guild

For a truly low-maintenance patch, consider creating a perennial guild. This is a group of plants that all support each other and the central crop—your blackberries—over many years.

A sample blackberry guild might include:

Blackberries (the central plant)
Comfrey (deep roots mine minerals; leaves make great mulch)
Bee Balm (for pollinators)
Chives (for pest repellent)
White Clover (living mulch that fixes nitrogen)

This system becomes more resilient and fertile each year. The plants work together almost like a team, which reduces your workload.

FAQ About Blackberry Companions

Can I plant strawberries with blackberries?
It’s not generally recommended. They can compete for space and nutrients, and they share susceptibility to some fungal diseases like verticillium wilt and anthracnose. It’s better to keep them in separate beds.

What is the best mulch for blackberries and their companions?
Wood chips, straw, or pine needles are excellent. They conserve moisture, suppress weeds, and break down to improve soil. Avoid using grass clippings that may contain weed seeds or herbicides.

Do blueberry companion plants work with blackberries?
Some overlap exists, as both like acidic soil. Plants like lupines (for nitrogen) and thyme can work well for both. However, always check each plant’s specific needs for sun and water, as blueberries have very shallow roots compared to blackberries.

How close can I plant companions to blackberries?
A good rule is to keep the area within a 12-inch radius of each blackberry crown mostly clear. Plant companions just outside this zone to avoid root competition and make sure you can prune and harvest the canes easily.

Will companion planting eliminate all pests?
No. Think of it as a helpful layer of defense, not a total cure. It reduces pest pressure and encourages natural predators, but you may still see some pests. The overall health of your plants will be better, making them more resilient to damage.

Using companion plants with your blackberries is a smart, natural strategy. It leads to a more beautiful and productive garden space. By choosing the right partners, you support your soil, manage pests, and create a thriving ecosystem right in your backyard. Start with one or two companions, like some chives and nasturtiums, and observe the benefits. You’ll likely find your garden becomes a more interesting and fruitful place.