Fertilising guide
How to fertilise Dwarf nasturtium (Tropaeolum minus)— schedule & NPK
Also called Dwarf nasturtium, Indian cress, Nasturtium.
More about dwarf nasturtium
About Dwarf nasturtium
Tropaeolum minus · also called Dwarf nasturtium, Indian cress · edible
Dwarf nasturtium is a compact, fast-growing annual with round, lily-pad-like leaves and vivid orange, yellow, or red flowers — both entirely edible with a peppery flavour. It thrives in poor to average soil with full sun and minimal watering. Avoid over-fertilising, which produces lush leaves at the expense of flowers.
Growth habit: Compact, mounding annual with round, waxy, peltate leaves on trailing or bushy stems; flowers held above foliage on long stalks
What fertiliser dwarf nasturtium actually wants — and why
Dwarf nasturtium is grown entirely for its leaves, so nitrogen is the priority — steady, nitrogen-leaning feeding keeps it growing fast, tender and unbolted.
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.
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 dwarf nasturtium: 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 dwarf nasturtium, 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 dwarf nasturtium:
Fertiliser is largely unnecessary and counterproductive in ground beds with average soil. If growing in containers with poor potting mix, a very dilute balanced liquid feed once a month is sufficient. High-nitrogen feeds produce all leaf and no flowers. 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 dwarf nasturtium 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 dwarf nasturtium
Use the vegetable-feed label rate for dwarf nasturtium. 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 dwarf nasturtium first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the dwarf nasturtium watering schedule.
Signs you are over-feeding dwarf nasturtium
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for dwarf nasturtium:
- 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 dwarf nasturtium
- 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 dwarf nasturtium care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
For container-grown dwarf nasturtium, 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 dwarf nasturtium
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 dwarf nasturtium — frequently asked questions
What fertiliser does dwarf nasturtium 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. Dwarf nasturtium 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 dwarf nasturtium?
Fertiliser is largely unnecessary and counterproductive in ground beds with average soil. If growing in containers with poor potting mix, a very dilute balanced liquid feed once a month is sufficient. High-nitrogen feeds produce all leaf and no flowers. Fertiliser is largely unnecessary and counterproductive in ground beds with average soil. If growing in containers with poor potting mix, a very dilute balanced liquid feed once a month is sufficient. High-nitrogen feeds produce all leaf and no flowers. 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 dwarf nasturtium?
Use the vegetable-feed label rate for dwarf nasturtium. Steady availability matters more than a strong dose — a check in growth makes leaves tough and can trigger bolting.
What does over-feeding dwarf nasturtium look like?
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. Letting dwarf nasturtium run short of nitrogen mid-crop is the main mistake — growth checks, leaves toughen and brassicas/leafy greens bolt or turn bitter. Keep nitrogen steadily available.
Should I flush the soil of dwarf nasturtium?
For container-grown dwarf nasturtium, 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.
Keep reading
- Dwarf nasturtium care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water dwarf nasturtium — the watering schedule
- The houseplant fertiliser schedule — feeding through the year
- NPK ratio explained — what the three numbers on the bottle mean
- How to fertilise crocus sativus
- How to fertilise passiflora edulis
- How to fertilise passiflora quadrangularis
- All 6887 fertilising guides in the Growli library