Fertilising guide

How to fertilise Savoy Cabbage (Brassica oleracea var. sabauda 'Savoy King')— schedule & NPK

Also called Savoy cabbage, curly cabbage.

More about savoy cabbage

About Savoy Cabbage

Brassica oleracea var. sabauda 'Savoy King' · also called Savoy cabbage, curly cabbage · edible

Savoy is a hardy heading cabbage with crinkled, blistered leaves forming a loose, tender head. The most cold-tolerant cabbage type, it stands through autumn and winter and sweetens with frost. Grow in full sun in firm, fertile, alkaline-leaning soil, keep it consistently moist, net against cabbage pests, and harvest heads as they firm up.

Growth habit: Biennial grown as an annual; a compact rosette of crinkled outer leaves wrapping into a rounded, slightly loose head atop a short stem.

Watch for — Clubroot: Swollen, distorted roots stunt and wilt plants in acidic, wet soil. Raise pH with lime, improve drainage, use a long rotation, and never replant brassicas in infected ground.

What fertiliser savoy cabbage actually wants — and why

Savoy Cabbage 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 savoy cabbage: 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 savoy cabbage, 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 savoy cabbage:

A heavy feeder. Base-dress generously with compost or balanced fertiliser, then side-dress with nitrogen once or twice during leafy growth before hearting. Ease off feeding as heads form to keep them firm rather than soft and split-prone. 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).

The dormant-season rule matters more than the exact interval: skip feeding entirely when savoy cabbage 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 savoy cabbage

Use the vegetable-feed label rate for savoy cabbage. 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 savoy cabbage first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the savoy cabbage watering schedule.

Signs you are over-feeding savoy cabbage

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

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 savoy cabbage

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 savoy cabbage care brief covers soil, humidity and the common problems for this species.

Flushing and leaching the salts

For container-grown savoy cabbage, 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 savoy cabbage

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 savoy cabbage — frequently asked questions

What fertiliser does savoy cabbage 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. Savoy Cabbage 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 savoy cabbage?

A heavy feeder. Base-dress generously with compost or balanced fertiliser, then side-dress with nitrogen once or twice during leafy growth before hearting. Ease off feeding as heads form to keep them firm rather than soft and split-prone. A heavy feeder. Base-dress generously with compost or balanced fertiliser, then side-dress with nitrogen once or twice during leafy growth before hearting. Ease off feeding as heads form to keep them firm rather than soft and split-prone. 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 savoy cabbage?