🌱 Canary Nasturtium

Grow in a well-drained, moderately fertile soil. Avoid very rich, high-nitrogen soils (they encourage leafy growth at the expense of flowers). If soil is heavy, improve drainage with grit/coarse sand and organic matter before planting.

Sow after risk of frost or start under cover for earlier growth. For best germination, lightly nick the hard seed coat and/or soak seeds 12–24 hours. Sow 1–2 cm deep in free-draining compost; keep evenly moist and warm. If started in pots/trays, pot on as needed and harden off before planting outside in full sun and well-drained soil. Avoid waterlogging and excessive nitrogen, which can reduce flowering.

Feed lightly only if growth is weak or soil is very poor. Use a low-nitrogen or balanced fertilizer at half strength; avoid frequent/high-nitrogen feeding to maintain flowering.

Mulch after planting to reduce evaporation and keep roots cool; keep mulch a few cm away from stems to prevent rot. In cool/wet periods, use a thinner mulch layer to avoid overly damp soil.

Climbing annual: provide support at planting (trellis, netting, wires, or canes with strings). Tie in young stems loosely until they start twining; guide shoots onto the support. Allow vertical clearance of at least 2–3 m.

Minimal pruning; pinch out growing tips early to encourage branching, and trim back overly long or tangled shoots to keep on the support.