Blackberries repay a little planning around what grows beside them. Blackberries are a vigorous cane fruit, often thorny, that fruits heavily once established, grown for fresh eating, pies and jam, grown along a fence or sturdy trellis. They need full sun, soil with a pH of 5.5–6.5, 36–48 inches of space and 365–730 days to reach maturity, so their neighbours need to suit the same bed and the same season. This guide lists the companions for blackberries from our crop data, how each one is thought to help, and which close relatives to keep apart.
There are 4 companions listed for blackberries here: Borage, Marigolds, Clover and Chives. Companion planting is traditional garden practice rather than proven science, so benefits below are described in those terms — what gardeners have long said and done. Blackberries are in the Rosaceae family, need moderate water, and are started indoors or sown direct; they are hardy and tolerate cold, so they can go out early in the season. Check any pairing first with the companion-planting finder.
Best companion plants for blackberries
| Companion | Why it is grown with blackberries |
|---|---|
| Borage | Borage flowers draw bees to the cane rows, and its leaves are traditionally said to encourage cane growth. |
| Marigolds | Grown as a border or dotted through the bed; its roots are traditionally said to discourage some soil pests, and its flowers attract beneficial insects. |
| Clover | A low living mulch that covers bare soil, keeps moisture in, and — as a legume — fixes nitrogen from the air into the soil. |
| Chives | A compact, clumping allium whose scent is traditionally said to confuse pests; its purple flowers attract pollinators. |
Borage is the first companion to reach for with blackberries, and they are big, vigorous plants, so companions go at the edges of the bed, not underneath the canes. Sow it direct at the edge of the bed and let it flower — the blue stars bring bees in from all over the garden, and those bees then visit everything around it. It self-seeds, so deadhead a few plants if you do not want it everywhere next year.
How companion planting works
Companion planting works through four overlapping mechanisms.
Pest confusion. Many pests find their host plant by scent. Strong-smelling companions such as Chives are traditionally said to mask that scent, so the pest passes by. It is a delaying effect, not a barrier.
Pollinator and beneficial-insect attraction. Several companions here flower — Borage, Marigolds, Chives — drawing pollinators and beneficial insects in. Let a few flower.
Nitrogen fixing. Nitrogen fixing applies here: clover is a legume, and legumes host bacteria on their roots that pull nitrogen from the air into the soil. This is the one companion-planting benefit with solid science behind it.
Ground cover and root layers. Ground cover does apply: clover spreads as a living mulch, shading the soil and holding moisture in.
None of this replaces the basics. Spacing, watering, rotation and weekly inspection matter more than any pairing.
Plants to avoid near blackberries
The plants to keep away from blackberries are its own relatives. Blackberries belong to the Rosaceae family, and plants in the same family share the same pests and diseases — here, aphids, Japanese beetles, birds, spider mites — so problems pass easily between them and build up in the soil.
| Plant to avoid | Why |
|---|---|
| Strawberries | Same Rosaceae family; shares pests such as aphids, Japanese beetles, birds, spider mites. |
| Raspberries | Same Rosaceae family; shares pests such as aphids, Japanese beetles, birds, spider mites. |
| Apples | Same Rosaceae family; shares pests such as aphids, Japanese beetles, birds, spider mites. |
| Pears | Same Rosaceae family; shares pests such as aphids, Japanese beetles, birds, spider mites. |
| Peaches | Same Rosaceae family; shares pests such as aphids, Japanese beetles, birds, spider mites. |
Keep these relatives in a different bed and rotate the Rosaceae family to fresh ground each year. Others in the same family in our crop data include Plums, Cherries, Roses.
Planting layout and spacing
Space 36–48 inches apart along a strong support and prune out fruited canes after harvest to keep the row open and airy.
Give blackberries their full spacing of 36–48 inches between plants. Crowded blackberries mean poor airflow, more disease and smaller harvests, and no companion plant compensates for it. Work out how many plants fit your bed with the plant-spacing calculator or the square-foot garden planner.
Plant companions in the spaces the spacing leaves, not instead of it. Low companions go in the gaps and along the bed edges; taller ones go at the north side so they do not shade the blackberries; scented herbs go closest to the crop, dotted through the row.
Blackberries are started indoors or sown direct: sow under cover where needed, expect germination in 14–28 days, and set plants out once the weather is right. Work backwards from your last frost date with the seed-starting calculator. Blackberries need full sun and soil with a pH of 5.5–6.5. Water needs are moderate, so keep the soil consistently moist with deep, regular watering rather than a light daily sprinkle, and mulch thickly to hold moisture in. The watering calculator gives a starting point for your bed size. Expect 365–730 days from sowing to maturity.
Common problems and fixes
The pests most often reported on blackberries are aphids, Japanese beetles, birds, spider mites. Companions may reduce pressure, but they do not prevent them — inspect leaf undersides and new growth weekly and act while numbers are low.
| Problem | What you see | First fix |
|---|---|---|
| Aphids | Sap-sucking insects on new growth; leaves curl. | Wash off with water; encourage ladybirds. |
| Japanese Beetles | Metallic green beetles skeletonise leaves in midsummer. | Hand-pick into soapy water in the morning. |
| Birds | Pecked fruit and stripped berries as they ripen. | Netting over the crop before fruit colours. |
| Spider Mites | Fine webbing and speckled, bronzed leaves in hot, dry weather. | Spray leaf undersides with water; raise humidity. |
Aphids
Wash them off with a strong jet of water and leave ladybirds and lacewings alone to eat them. Check the undersides of young leaves, where colonies start.
Japanese Beetles
Hand-pick beetles into a bucket of soapy water in the cool of the morning, when they are sluggish. Traps lure more beetles in than they catch, so keep them far from the crop.
Birds
Net the crop before the fruit starts to colour — once birds have found it, they return daily. Drape netting over hoops so it does not tangle in the branches.
Spider Mites
Spider mites thrive in hot, dry conditions. Spray leaf undersides with water regularly and avoid dusty, drought-stressed plants, which are hit hardest.
Unsure what you are seeing? Try the pest-identifier helper or the plant-disease checker. Remove badly affected leaves and rotate the Rosaceae family next year.
Frequently asked questions
What is the best companion plant for blackberries?
The most widely recommended companion is borage. Borage flowers draw bees to the cane rows, and its leaves are traditionally said to encourage cane growth.
What should not be planted near blackberries?
Avoid other members of the Rosaceae family, including Strawberries, Raspberries, Apples, Pears. They share the same pests and diseases as blackberries, so problems move easily between them. Rotate the family to a fresh bed each season.
Can I plant blackberries with marigolds?
Yes. Marigolds are on the companion list for blackberries. Grown as a border or dotted through the bed; its roots are traditionally said to discourage some soil pests, and its flowers attract beneficial insects.
How far apart should blackberries and their companions be planted?
Space blackberries plants 36–48 inches apart, and put companions in the gaps, along the edges and at the ends of rows. The plant-spacing calculator works out how many plants fit your bed.
Does companion planting replace pest control?
No. It may reduce pest pressure, but it does not replace inspection, spacing, watering, rotation and good airflow. Check plants weekly and act early.