How to grow snapdragon
Overview
Snapdragon is a short-lived herbaceous perennial grown as an annual for its tall spikes of colourful, tubular flowers. It is prized for adding vertical interest and filling gaps in garden beds during the cooler months.
Varieties
- Rocket Series — Tall, vigorous spikes in a range of colours; excellent for cut flowers in Australian gardens.
- Madame Butterfly — Double, azalea-like flowers in pastel shades; popular for borders and containers.
- Snappy — Compact, early-flowering series ideal for pots and small spaces; heat-tolerant.
Soil Preparation
Snapdragon prefers a slightly acidic to neutral pH (6.0-7.0). Enrich soil with well-rotted compost or aged manure before planting. Ensure good drainage to prevent root rot.
Growing Guide
Plant snapdragon in full sun with well-drained soil enriched with organic matter. Sow seeds directly or start indoors 6-8 weeks before the last frost, barely covering them. Space plants 20-30 cm apart. Pinch out the growing tip when 10 cm tall to encourage bushy growth. In hot weather, provide afternoon shade and mulch to keep roots cool.
Sowing
Sow snapdragon seeds on the surface of moist seed-raising mix, barely covering them. Germination takes 7-14 days at 18-21°C. Transplant seedlings when they have 4-6 true leaves, spacing 20-30 cm apart.
Care
Feed with a balanced liquid fertiliser every 2-3 weeks during active growth. Deadhead spent flowers regularly to extend blooming. Cut back leggy stems in late summer to encourage a second flush of flowers.
Companion Planting
Good companions include dianthus, salvia, and lobelia. Avoid planting near rust-prone plants like hollyhocks. Marigolds and nasturtiums nearby can help deter aphids.
Common Pests & Risks
Aphids often cluster on new growth; spray with a strong jet of water or use insecticidal soap. Rust appears as orange pustules on leaves; remove affected leaves and improve air circulation. Powdery mildew shows as white coating; avoid overhead watering and apply a sulfur spray if needed.
Harvesting
Harvest snapdragon stems for cut flowers when the lowest 2-3 flowers on the spike are open. Cut early in the morning and place in water immediately. Regular picking encourages more blooms.
Troubleshooting
Yellow leaves: overwatering or poor drainage; reduce watering and improve soil. Brown leaf edges: underwatering or heat stress; increase water and provide shade. Leggy growth: insufficient light; move to a sunnier spot. Stunted growth: root rot from soggy soil; replant in well-drained mix. Flowers not opening: rust infection; remove affected leaves and treat with fungicide.