Transplant outside
2–4 weeks before last frost
Best as a permanent bed; needs 18 in of well-drained soil and room for arching canes. In containers: 20-gallon container, at least 18 in deep and wide. Space plants 30 inches (75 cm) apart.
Crop guide · The rose family
How to grow Black Raspberry
A native bramble with arching, blue-dusted canes that carry tight clusters of small, deep purple-black berries for about three weeks in early summer.
Rubus occidentalis · also called Blackcap, Blackcap raspberry
Full sun
Intermediate
Frost-hardy
Sun
Full sun
Light afternoon shade where summers regularly top 90 °F (32 °C) keeps ripening berries from scalding.
Frost
Hardy
Dormant canes take hard freezes. Open spring blossoms are damaged below about 30 °F (-1 °C)
Spacing
30 in
75 cm between plants
Sow depth
2 in
51 mm
Timing
When to plant Black Raspberry
Spring
Transplant
Set dormant plants 2–4 weeks before last frost, as soon as soil is workable.
Fall
Transplant
Where winters are mild, plant 6 weeks before the ground freezes.
Too late?Skip planting once canes have leafed out and hot weather has set in; wait for the next dormant window in late winter.
Background
Why grow Black Raspberry
The fruit is too soft to ship, so growing your own is the practical way to get it. One planting produces for ten years or more on nothing but annual pruning and a spring feeding.
A little history. Native to eastern North America. Each cane lives two years: it grows one season, fruits the next, then dies. Arching tips root where they touch soil, which is how growers start new plants.
The season, step by step
From planting to harvest
Water and feed
All season
One deep soak a week; two while berries are sizing and ripening. Water when soil 2 in down feels dry at the base of the canes. Aim for 1 to 1.5 inches per week including rain.
Once in early spring before new shoots push; skip late-summer feeding. What to use: 1 inch of compost or a balanced 10–10-10 spread along the row and watered in.
Prune and maintain
As it grows
In summer, cut new shoots back at 24–36 in tall to force side branches. After harvest, cut spent fruiting canes to the ground. In late winter, shorten side branches to 8–12 in.
Harvest and store
When it's ready
It's ready when berries turn dull black, lose their shine, and drop into your hand at a light tug. Red or glossy fruit is not ripe and will be sour. Cup the berry and roll it off with your thumb; ripe fruit slips free of its core, leaving a hollow cap. Pick into shallow containers no more than 4 in deep so the bottom layer is not crushed.
Refrigerate unwashed in a single shallow layer and eat within 2–3 days. Wash only at serving time; wet berries break down fast.
Overwintering
Canes are hardy without protection in most areas. Spread 2–3 in of mulch over the root zone after the ground cools, keeping it off the cane bases.
Companions
Good neighbours, bad neighbours
Plant it with
Sweet Alyssum
Low mats of alyssum bloom for months and draw in hoverflies whose larvae eat aphids. Aphids matter here beyond the leaf damage: they carry the viruses that shorten a black raspberry planting's productive life.
Yarrow
Flat yarrow flower heads feed lacewings and tiny parasitic wasps that work over aphid colonies on cane tips. Set it at row ends rather than in the picking alley, where it would be trampled.
Borage
Borage flowers steadily through early summer and pulls bumblebees into the planting. Each berry is a cluster of many small segments, and flowers worked thoroughly by bees set full, cohesive fruit instead of crumbly ones.
White Clover
A mown clover alley between rows holds soil under picking traffic, keeps mud off low fruit, and crowds out weeds. Keep it out of the 12-inch strip at the base of the canes, where it would compete for water.
Comfrey
Comfrey roots run far below the bramble's shallow feeder roots, so the two rarely fight over water at the row end. Cut leaves lay down as a coarse mulch under the canes.
Keep it away from
Raspberry
Aphids move viruses from red raspberries into black raspberries, which are far more sensitive and can decline within a few years. Extension guidance is to plant black raspberries at least 300 feet away, upwind if possible, and to pull wild brambles nearby.
The Nightshade Family
Tomatoes, peppers, potatoes, and eggplant build up the soil fungus that causes wilt, and it survives for years after those crops are gone. Black raspberry canes then die off one at a time in midsummer. Choose ground that has not grown them for 4 years.
Strawberry
Strawberries host the same soil-borne wilt fungus as the tomato family, so an old strawberry patch is a poor site for a new bramble row. Keep the two plantings separate and allow several years between them on the same ground.
Crop rotation
After this crop
Rotation
A perennial — it holds its spot for years, so it sits outside the annual rotation.
This is a permanent planting, not part of any rotation — expect 10 years or more from one row. Choose the site carefully once: avoid ground that grew tomatoes, peppers, potatoes, eggplant, or strawberries in the past 4 years, since wilt fungus lingers there.
Trouble to watch for
Pests and diseases
Pests
Spotted wing drosophila
Sign
Ripe berries collapse within a day of picking; tiny white maggots show when fruit sits in salt water.
Fix
Pick every 1-2 days, chill fruit right away, and bag or bury all overripe and dropped berries.
Raspberry cane borer
Sign
Shoot tips wilt and hang over, with two neat rings girdled into the cane an inch apart below the wilt.
Fix
Snip the cane 6 in below the lower ring and destroy the cutting; check tips weekly in early summer.
Aphids
Sign
Clusters of small green insects on shoot tips and the undersides of young leaves; leaves curl and turn sticky.
Fix
Spray tips with a strong jet of water, then repeat in 3 days. Leave flowering plants nearby to feed aphid predators.
Japanese beetle
Sign
Leaves skeletonized to lace between the veins in midsummer, with copper-green beetles feeding in groups.
Fix
Knock beetles into soapy water in the early morning. Do not hang lure traps near the planting.
Diseases
Anthracnose
Sign
Small purple spots on new canes that widen into sunken gray centers; bad canes crack and dry out.
Prevent
Thin to 4-6 canes per crown for airflow, cut out old canes right after harvest, and avoid overhead watering.
Orange rust
Sign
Spring leaves narrow and pale, then bright orange powder coats the undersides; the plant never fruits well again.
Prevent
Dig out and destroy infected plants, roots and all, as soon as you see it. Remove wild brambles within sight of the row.
Verticillium wilt
Sign
Canes wilt and die one at a time in midsummer, lower leaves yellowing upward while neighbors stay healthy.
Prevent
Do not plant where tomatoes, peppers, potatoes, eggplant, or strawberries grew in the past 4 years. The fungus persists in soil.
Virus complex (mosaic and leaf curl)
Sign
Mottled, puckered, or downcurled leaves; canes shorten and berries turn small and crumbly over several seasons.
Prevent
Buy certified virus-free plants, keep 300 feet from red raspberries and wild brambles, and control aphids that carry it.
FAQ
Common questions about Black Raspberry
When should I plant Black Raspberry?
Spring: set dormant plants 2–4 weeks before last frost, as soon as soil is workable. Fall: where winters are mild, plant 6 weeks before the ground freezes.
Can I grow Black Raspberry in a container?
Best as a permanent bed; needs 18 in of well-drained soil and room for arching canes. In containers: 20-gallon container, at least 18 in deep and wide.
How often should I water Black Raspberry?
One deep soak a week; two while berries are sizing and ripening. Water when soil 2 in down feels dry at the base of the canes.
How should I store Black Raspberry after harvest?
Refrigerate unwashed in a single shallow layer and eat within 2–3 days. Wash only at serving time; wet berries break down fast.
Can Black Raspberry stay in the ground over winter?
Canes are hardy without protection in most areas. Spread 2–3 in of mulch over the root zone after the ground cools, keeping it off the cane bases.
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