Fertilising guide

How to fertilise Black Redcurrant (Ribes nigrum 'Ben Lomond')— schedule & NPK

Also called Ben Lomond blackcurrant.

More about black redcurrant

About Black Redcurrant

Ribes nigrum 'Ben Lomond' · also called Ben Lomond blackcurrant · edible

'Ben Lomond' is a reliable, heavy-cropping blackcurrant valued for its late flowering, which dodges spring frosts, and its good mildew resistance. It bears large, tart, vitamin-C-rich berries in mid-summer on a sturdy, upright bush. Hardy and easy in any sunny or part-shaded spot with rich, moist soil, it suits jam, cordials, and freezing.

Growth habit: Vigorous, upright deciduous shrub that fruits best on one- and two-year-old wood. Pruned by removing about a third of the oldest stems to the base each winter, it renews itself continually and stays productive for many years.

Watch for — American gooseberry mildew: White powdery growth on shoots and fruit. 'Ben Lomond' has some resistance; improve airflow with open-centre pruning and avoid excess nitrogen-driven soft growth.

What fertiliser black redcurrant actually wants — and why

Black Redcurrant is grown entirely for its leaves, so nitrogen is the priority — steady, nitrogen-leaning feeding keeps it growing fast, tender and unbolted.

For the language behind the three numbers on the bottle — what nitrogen, phosphorus and potassium each do — see the NPK ratio explained entry. The short version for black redcurrant: match the feed to the job the plant is doing right now, not to a generic “plant food” on the shelf.

How often to feed black redcurrant, and which months

Feeding only earns its keep while the plant is in active growth and can use the nutrients — pour feed into a dormant or low-light plant and it simply builds up as root-burning salt. For black redcurrant:

The dormant-season rule matters more than the exact interval: skip feeding entirely when black redcurrant is resting. For the wider context on indoor feeding rhythms across the seasons, the houseplant fertiliser schedule walks through the year month by month.

What strength to mix for black redcurrant

Use the vegetable-feed label rate for black redcurrant. Steady availability matters more than a strong dose — a check in growth makes leaves tough and can trigger bolting.

Feeding always goes onto already-damp soil, never dry roots — water black redcurrant first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the black redcurrant watering schedule.

Signs you are over-feeding black redcurrant

Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for black redcurrant:

Very soft, floppy, dark-green growth that attracts aphids.
Excess leafy growth at the expense of hearts/heads in cabbage and the like.
Salt crust and scorched leaf edges in containers; nitrate-heavy leaves.

Signs you are under-feeding black redcurrant

Pale, yellow-green leaves, oldest first, and slow growth.
Small, tough, bitter leaves and premature bolting.
Weak, stunted heads in cabbage, broccoli and cauliflower.

If the symptoms point at watering, light or roots rather than nutrition, the full black redcurrant care brief covers soil, humidity and the common problems for this species.

Flushing and leaching the salts

For container-grown black redcurrant, water until it drains freely each time and flush pots monthly with plain water to stop nitrogen salts accumulating; in the ground, good compost levels naturally buffer this.

Organic vs synthetic feeds for black redcurrant

Organic options

Well-rotted manure or compost dug in, plus nitrogen-rich liquid feeds like diluted chicken-manure pellets or nettle feed. UK: pelleted chicken manure or Westland; US: Espoma Garden-tone or blood meal. Steady and soil-building.

Synthetic / liquid feeds

A balanced feed at planting then a high-nitrogen liquid or granular side-dress — UK: Growmore then a nitrogen feed or Phostrogen; US: a 10-10-10 then a high-N (e.g. 21-0-0) side-dress or Miracle-Gro.

Brand names are examples, not endorsements, and UK and US ranges differ — check the label’s own NPK and dilution rate, since formulations change.

Fertilising black redcurrant — frequently asked questions

What fertiliser does black redcurrant need?

A nitrogen-leaning feed (higher first number) or compost-rich soil — nitrogen drives the fast, tender leafy growth this crop is grown for. Phosphorus and potassium matter far less here than for fruiting crops. Black Redcurrant is grown entirely for its leaves, so nitrogen is the priority — steady, nitrogen-leaning feeding keeps it growing fast, tender and unbolted.

How often should I feed black redcurrant?

Blackcurrants are nitrogen-hungry: apply a high-nitrogen feed or well-rotted manure in late winter, plus a balanced general fertiliser in spring. A potassium boost supports fruiting. Mulch annually with manure or compost, which feeds and conserves moisture. Avoid high potash/lime regimes meant for other fruit. Blackcurrants are nitrogen-hungry: apply a high-nitrogen feed or well-rotted manure in late winter, plus a balanced general fertiliser in spring. A potassium boost supports fruiting. Mulch annually with manure or compost, which feeds and conserves moisture. Avoid high potash/lime regimes meant for other fruit. In practice: a balanced or compost-rich start, then a nitrogen side-dress or liquid feed every 3-4 weeks through the cropping period in the main season (spring through early autumn).

What strength of feed for black redcurrant?