Blackcurrants

Question 1

Name three cultivars of blackcurrant.

Answer 1

• Blackdown
• Wellington XXX
• Baldwin.

Question 2

Blackcurrants are a cool climate bush fruit, so explain site and soil selection.

Answer 2

• Well-drained, moisture-retentive soil
• Fertile loam
• Sunny or lightly shade site
• pH of 6.5 - 7
• Protection from severe frosts as flower in April.

Question 3

Explain planting of blackcurrants.

Answer 3

• Choose certified disease-free stock
• Plant in early winter or early spring
• Plant deeper than they were in the nursery to encourage multiple stems at ground level
• After planting, prune back all branches to 3cm above ground level.

Question 4

Explain cultivation of blackcurrants.

Answer 4

• Protect from frost as they flower early
• Weed around base of bush (do not cultivate deeply)
• Mulch regularly
• Fertilise annually with top dressing of Growmore at 110g/sqm or blood and bone at 70g/sqm
• Top dressing of potassium sulphate at 35g/sqm in mid spring
• Irrigate w 20l/sqm in dry weather, esp after fruit set
• Protect against birds.

Question 5

Explain harvesting and storage of blackcurrants.

Answer 5

• Harvest fruit when they are ripe yet still firm
• Pick the whole bunch rather than single berries
• Eat while fresh or store by bottling, freezing or making jam.

Question 6

Explain the pruning of blackcurrants

Answer 6

• Fruit best on strong stems from previous year
• Prune in winter (Nov-Dec) by removing a third of stems that have fruited (darker in colour)
• Do not remove strong stems produced that season (paler) as these will fruit next year
• Prune out low-lying branches and weak growth at ground level.

Question 7

Name a pest and a disease of blackcurrants, including symptoms and control methods.

Answer 7

Big bud mite

• Sucker pest causes buds to swell over winter
• Cut out and burn in winter.

Reversion virus

• Leaves change shape from palmate to diamond shape with bigger, wider-spaced veins and fewer serrations. Flower buds are red. Vigour reduced
• Destroy infected plants. Buy certified stock and plant on fresh site.