Soft fruit (cane)
How to grow blackberries
Rubus fruticosus agg.
Plant a blackberry between November and March against wires on a fence or posts, in sun or light shade and any fertile soil that holds some moisture. Choose a thornless variety sized to the space, because vigour is the thing that catches people out. Success comes down to training: keep this year's new canes tied apart from the canes that are fruiting, then cut the fruited ones to the ground after picking. The flowers are busy with bees in early summer, so a trained blackberry earns its keep in wildlife gardening as well as in the kitchen. Feeding is light.
- Hardiness
- Fully hardy
- Position
- Sun to light shade
- Soil
- Fertile, moisture-retentive
- Ideal pH
- 6.0 to 7.0
- Water
- Moderate
- Feeding
- Moderate feeder
Sowing and planting blackberries
WhenPlant Nov to Mar; harvest Jul to Oct by variety
Starting off
Plant bare-root Nov to Mar or pot-grown any month. Propagate by tip layering in Aug to Sep, bury a cane tip 10 cm deep, sever and move the rooted plant in spring, or by leaf-bud cuttings in Aug. Loch Ness and Oregon Thornless are thornless and self-fertile.
Spacing and planting
Compact types (Loch Ness, Loch Tay) 2.5 m apart, vigorous Oregon Thornless 4 m; wires at 90, 120, 150 and 180 cm. Plant the crown at soil level and cut canes to 25 cm. Loch Ness or a dwarf patio type grows in a 45 cm pot; vigorous types do not.
Varieties worth growing
- Loch Ness
- Thornless and compact with stiff, fairly upright canes; heavy crops from mid August and the best choice for a small garden or large pot.
- Loch Tay
- Thornless and early, picking from July, with sweet fruit that needs little sugar.
- Oregon Thornless
- Vigorous, with decorative cut leaves; crops late, from the end of August, and covers a long fence or arch.
- Karaka Black
- Very long, large berries from July over a long season; thorny, so wear gloves.
- Reuben
- Primocane type that fruits in September and October on canes grown the same year, so pruning is one cut to the ground in February.
Blackberries month by month
Timings are for central England. Allow two weeks later in the north and on cold, heavy soil.
- January
Plant bare-root plants in open weather. Check posts and tighten wires.
- February
Tip-prune canes and cut frost-damaged ends back to sound wood. Cut primocane types such as Reuben to the ground.
- March
Light feed, then an 8 cm mulch. Last bare-root planting.
- April
New canes appear from the base. Start tying them in a loose bundle up the centre, away from the fruiting canes.
- May
Keep tying in new canes. Water plants set out last winter in dry spells.
- June
Flowering. Water in drought, since dry roots now mean small, seedy fruit later.
- July
Loch Tay and Karaka Black start. Pick every three to four days. Net if birds are taking fruit.
- August
Main picking for Loch Ness. Tip-layer a cane now if you want a new plant.
- September
Pick Oregon Thornless and Reuben. Begin cutting out canes that have finished fruiting.
- October
Cut all fruited canes to the ground, then untie the new canes and fan them out along the wires.
- November
Plant bare-root plants with the crown at soil level and cut to 25 cm.
- December
Plant in open weather. Otherwise nothing to do.
Feeding blackberries
A vigorous plant that needs little. On decent soil an annual mulch is enough; feed only young plants, plants in pots, or plants on thin soil.
Low-to-moderate, vigorous, so a spring mulch and a light feed is plenty.
Feeding plan
Planting, November to March
5 g per litre of root-ball volume, touching the roots, once: 15 g for a plant from a 3 litre pot.
March, every year
Garden compost
A mulch 8 cm deep over about 1 m each side of the crown. On fertile soil this is the whole feeding plan for an established plant.
March, first two years or on poor soil
Fruit & Vegetable Fertiliser 4-5-6
70 g/m², the lower end of the label, over roughly 2 m² around the crown: 140 g per plant, once. Stop if canes exceed 4 m and fruit is sparse.
March, plants in pots
Fruit & Vegetable Fertiliser 4-5-6
2 g per litre of compost as a top-dress: 80 g for a 45 cm pot holding about 40 litres.
Signs to watch
Rampant canes over 4 m and few fruit
Nitrogen excess
Stop feeding; a spring mulch is enough
Pale small leaves and thin canes
Nitrogen short, rare
Balanced spring feed
Older leaves yellow between the veins
Magnesium
Epsom salts or kieserite
Fruit small and seedy
Drought
Mulch and water in July
Pests, diseases and problems
Some drupelets stay hard and red while the rest of the berry turns black, mostly late in the season
Redberry mite feeding on the developing fruit
There is no treatment. Early fruit is rarely affected, so pick it and accept some loss later; cutting out all fruited canes promptly after harvest removes many of the mites.
Ripe fruit collapses and leaks, with tiny white maggots inside
Spotted wing drosophila, a fruit fly that attacks sound ripening fruit from late summer
Pick every two to three days and never leave overripe or fallen fruit on the plant or ground. Bin or drown damaged fruit rather than composting it. Fine insect mesh over the plant keeps the fly off.
Small white grubs in the fruit, dry brown patch at the stalk end
Raspberry beetle, which also attacks blackberries and hybrid berries
Hang a raspberry beetle trap from late April where damage was bad the year before. Late varieties are less affected.
Grey fluffy mould on berries in wet weather
Grey mould (botrytis)
Space the canes out on the wires so air moves through, pick often and remove mouldy fruit.
Small purple spots with grey centres on canes and leaves; canes may crack and die back
Cane spot, a fungal disease that spreads in wet springs
Cut out and bin badly spotted canes, keep new canes thinned and tied in, and avoid heavy nitrogen feeding.
Ripe berries pecked or stripped
Birds
Drape netting over the wires as the first berries colour. A big established plant usually crops enough to share.
Pruning and harvest
Pruning and care
Fruits on last year's canes: after harvest in Sep to Oct cut fruited canes to the ground and tie the new canes, trained separately through summer, onto the wires in a fan or rope. Tip prune in Feb. Primocane types (Reuben) are cut to the ground in Feb and crop on new canes. Mulch 8 cm in spring.
Harvest and storage
Ripe when black, dull rather than glossy, and slightly soft; it pulls off with its plug. Pick every 3 to 4 days Jul to Oct by variety. Crops from the second year; 5 to 10 kg per plant from a thornless bush, more from a vigorous one. Fridge 2 days; freeze, jam, or bottle.
Good to knowTrain the new canes separately from the fruiting ones; thornless cultivars are far easier to manage.
Growing blackberries in pots
Only compact varieties suit a pot: Loch Ness or one of the dwarf patio blackberries, in a 45 cm container holding about 40 litres of peat-free loam-based compost. Mix in the 4-5-6 at 5 g per litre (200 g) when potting. Push three or four tall canes in round the rim and tie the growth to them, new canes to one side and fruiting canes to the other. Water daily in hot weather from flowering to the end of picking. Top-dress every March and repot into fresh compost every two to three years.
Blackberries: common questions
When should I prune blackberries?
Prune straight after harvest, in September or October, by cutting every cane that has fruited down to the ground. Then tie this year's new canes onto the wires in their place and shorten any frosted tips in February. Primocane varieties such as Reuben are different: cut all canes down in February.
Why are my blackberries not turning black?
Berries that stay partly red and hard are damaged by redberry mite, which is common late in the season and cannot be treated. Berries that are simply slow need more time: a blackberry is ripe a few days after it turns black, when it goes dull and soft.
Will blackberries fruit in shade?
Yes, blackberries crop in light shade and on a north or east-facing fence, which few other fruits manage. The fruit ripens later and is a little less sweet than in full sun.
Sources
Growing information on this page was checked against these references in November 2026. Feeding rates are Dr Forest label rates.