How to grow nasturtium flower
Overview
Nasturtium flower (Tropaeolum majus) is a fast-growing trailing annual grown for its peppery edible flowers and leaves. It thrives in poor soil with minimal care, producing abundant blooms when not overfed.
Varieties
- Alaska — Variegated cream-and-green leaves, compact habit, good for pots.
- Empress of India — Deep crimson flowers, dark green leaves, early to bloom.
- Jewel Mix — Mixed colours including cream, orange, and red; semi-double flowers.
Soil Preparation
Nasturtium prefers poor to average soil with a pH of 6.0–7.0. Do not add compost or manure; rich soil reduces flowering. Ensure good drainage — add sand or gravel if clay-heavy.
Growing Guide
Sow seeds 1 cm deep in well-drained soil after the last frost. Space plants 25–30 cm apart; they will sprawl. For best flowering, grow in part shade with only 4–6 hours of morning sun. Water regularly but avoid wetting the foliage to reduce mildew. Pinch out growing tips at 4 leaves to encourage bushiness.
Sowing
Sow seeds 1 cm deep, 2–3 per hole, 25 cm apart. Germinates in 7–14 days at 15–20°C. Direct sow is best; transplant only if necessary and handle carefully.
Care
Feed only with a low-nitrogen liquid fertiliser every 4 weeks to keep flowers coming. Pinch back leggy stems to maintain a compact shape. Remove spent flowers to extend the season.
Companion Planting
Plant nasturtium near brassicas to repel cabbage white butterflies. It also works well with tomatoes and cucumbers as a living mulch. Avoid planting near beans or peas, as they compete for nutrients.
Common Pests & Risks
Aphids and cabbage white caterpillars are common. Spray aphids with a strong jet of water or neem oil. Hand-pick caterpillars. Avoid overhead watering to prevent powdery mildew.
Harvesting
Pick flowers and leaves when fully open, before they fade. Harvest regularly to encourage more blooms. Use fresh within a day; store in a damp paper towel in the fridge for up to 3 days.
In the Kitchen
Use fresh flowers and leaves in salads for a peppery kick. Stuff flowers with cream cheese or use as a garnish. Leaves can be used like watercress in sandwiches.
Troubleshooting
Yellow leaves: overwatering or poor drainage — let soil dry out. Brown edges: too much sun or wind — move to part shade. No flowers: too much nitrogen — stop feeding and add a pinch of potassium. Leggy stems: too little light — pinch back and move to brighter spot.