Black raspberry

Black raspberry: how do you recognise it?

Habit

Shrub 1.5–2 m tall and 1–1.5 m wide, with arching stems covered in a grey-blue bloom and hooked prickles.

Canes

Biennial: a cane grows in its first year, fruits in its second year and then dies.

Foliage

With three or five leaflets, dark green above and greyish white beneath, with a toothed edge.

Flower

Small white to greenish white flowers in small clusters, in May and June.

Fruit

Glossy black, raspberry-like fruits in July, sweet and aromatic with lots of small seeds.

Roots

Tip-rooting: the tips of the long shoots arch to the ground and root there. No suckers.

Flowering: May–June · Harvest and fruit: June–July · Plants: March–April and October–November · Pruning: February–March and June–August

Why grow it?

• Dark, aromatic fruits in July, which you rarely find in the shops.
• Does not form invasive suckers: a manageable shrub for the fruit patch.
• The flowers in May and June are a good food source for bees and bumblebees.
• Birds love the berries: the shrub is also a summer table for them.
• Fully hardy down to about −30 °C and also suited to half shade.
• Eat the fruits fresh or make them into jam, tart or ice cream.

Black raspberry: where does it grow best?

• Sun to half shade: in full sun they crop most heavily and the fruits are sweetest.
• Free-draining, humus-rich soil: sand, loam or clay, acid to neutral.
• Normally moist, especially while the fruit sets in June–July, but no wet feet. Sheltered from strong wind.
• Plant 1–1.5 m apart, with rows 2 m apart, so you can pick easily.
• Not on ground where tomatoes, potatoes or strawberries grew before: risk of verticillium wilt.

Light

Sun and partial shade

Soil type

Sand, loam or clay

Acidity

Acid or neutral

Moisture

Normal

Size

2 m tall, 1.5 m wide

Hardiness

Hardy (to -30 °C)

Goes well with

• Redcurrant: Similar care in the same fruit patch.
• Gooseberry: Fits in the same fruit patch and flowers early for bees.
• Pot marigold: Attracts bees and hoverflies, which help keep aphids in check.
• Chives: A low edging at the base that flowers in May–June for pollinators.

Black raspberry: when and how to plant it?

Plant in March–April and October–November.

1. Plant in March–April or in October–November, when the soil is neither frozen nor waterlogged.
2. Dig a hole about 40 cm wide, remove weeds and mix compost into the soil.
3. Set the plant at the same depth as in the pot or nursery. For a bare-root plant, cut the cane back to about 20 cm.
4. Run one or two wires along the row at 1 m and 1.5 m high, or add posts to tie the canes to.
5. Water in generously straight away, even if it is raining, and firm the soil.
6. Spread a 5–10 cm layer of compost or bark mulch, keeping it clear of the canes.

Care

Water

In dry summers, water generously once a week, especially while the fruit sets and ripens in June–July. Water at the base.

Feeding

In March, a spadeful of compost or organic fertiliser per plant. Not too much nitrogen: the canes become soft and weak.

Mulching

A layer of compost or bark keeps the soil moist and weed-free. Do not hoe deeply: the roots are shallow.

Support

Tie the canes to wires or posts; the long, arching shoots otherwise bend or break under the weight of fruit and in wind.

Harvest

Pick in July when the fruits are glossy black and come away easily. Pick every 2–3 days and use them quickly.

Birds

Drape netting over the shrub while the fruit ripens if you want to keep the crop for yourself.

Tip: Pinch the young shoots at 60 cm in June: the shrub branches and you get more fruiting wood. Do not let tips root in the ground if you do not want new plants.

Black raspberry: when to prune it?

Pruning months: February–March and June–August.

When: Three moments: in June pinch out the young shoots, in July–August cut out the canes that have fruited, and in February–March shorten the side shoots.

How:

• In June, pinch the tips of the young shoots at about 60 cm: they branch and become sturdier.
• After harvest (July–August), cut the canes that bore fruit down to the ground; they die anyway.
• Leave 3–5 strong young canes per plant and tie them to the wires.
• In February–March, shorten the side shoots to about 30–40 cm: this gives bigger fruits.

Caution: Cut out the fruited canes only after harvest. Wear gloves: the canes have hooked prickles.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Tip layering

In August–September: bend the tip of a long shoot down to the ground, bury it 5–8 cm deep and pin it down. It roots in 4–6 weeks; separate it in autumn or the following spring.

Seed

Possible, but cultivars do not come true from seed and the seeds need a cold period of a few months. Less suitable at home.

Black raspberry: how does it get through the winter?

Hardy to −30 °C.

• Fully hardy down to about −30 °C: no protection needed in Flanders.
• In hard frost the cane tips may die back. That does not matter: you cut them off in February–March.
• Leave the canes on the wires and add an extra layer of compost or bark around the base in November.

Diseases and pests

• Anthracnose: Purple to grey spots on the canes; they may split and die. Cut out affected canes, keep the shrub airy and remove the prunings.
• Verticillium wilt: Leaves wilt, the canes turn blue-black and die. Do not plant where tomatoes, potatoes or strawberries grew and remove affected plants.
• Raspberry beetle: Small white grubs in the fruits. Pick regularly and clear up fallen fruits.
• Aphids: On the young shoots; they can spread viruses. Rinse them off with water and let ladybirds do the work.

Through the year

• February: Shorten the side shoots to 30–40 cm. Put up the wires.
• March: Plant. Give compost.
• April: Apply mulch. Tie in the new shoots.
• May: Flowering starts. Water in dry weather.
• June: Flowering and fruit set. Pinch the young shoots at 60 cm.
• July: Harvest. Net against birds. After harvest, cut out the old canes.
• August: Cut out fruited canes. Layer the tips.
• September: Pin down the layers. Remove the last old canes.
• October: Plant. Apply mulch.
• November: Plant. Give compost.

Edible and useful

Fruit (June–July)

The berries ripen in June and July: first red, then glossy black. Pick them when they are black and come away easily; they are hollow, like a raspberry. They taste sweeter and spicier than raspberries, with less acidity: fresh, in jam, syrup, ice cream or over yoghurt. They stain everything deep purple.

Storing

Fresh, one to two days in the fridge, unwashed. Frozen (spread on a tray), a year.

Caution: Black raspberries are safe. They stain hands, clothes and chopping boards deep purple. The canes are prickly: wear gloves. Do not confuse them with blackberries, which are not hollow and ripen later; both are edible.

Eating and using is at your own risk: see the terms of use.

Recipes

• Black raspberry syrup (Syrup · ± 750 ml · 30 min)

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Birds

Berries, seeds or insects as food, or a place to nest.

Did you know?

• In North America the species is also called ‘blackcap’, after its black fruits.
• As with an ordinary raspberry, the fruit leaves its core on the plant when picked, so it is hollow. With a blackberry you pick the core along with the fruit.
• The grey-blue bloom on the stems is a natural protection against water loss.