Snapdragons (Antirrhinum majus) are vibrant, eye-catching flowering plants beloved for their distinctive dragon-shaped blooms that open and close when gently squeezed — hence the charming common name. They produce tall, upright spikes adorned with densely packed flowers in an extraordinary range of colours, including pink, red, yellow, orange, white, purple, and striking bi-colour varieties.

Snapdragons are cool-season performers, thriving in mild temperatures and often planted in spring or autumn when the weather is fresh. They are excellent pollinator plants, attracting bees and butterflies, and their long-lasting cut flowers make them a popular choice for floral arrangements and cottage-style borders.

Plants range from compact dwarf varieties of around 15–20 cm to tall cultivars reaching 90 cm or more. Their edible blooms add a mild, slightly bitter flavour as a garnish in salads and dishes. Whether grown as annuals or short-lived perennials depending on local climate, snapdragons bring remarkable colour, texture, and vertical drama to garden beds, borders, and containers throughout the growing season.

How To Grow

How to Grow Snapdragons

Starting from Seed

Sow seeds indoors 8–10 weeks before the last expected frost. Snapdragon seeds are very fine — press them lightly onto the surface of moist seed compost and do not cover them, as they need light to germinate. Maintain a soil temperature of 15–21°C for best germination. Seedlings typically emerge within 10–14 days.

Transplanting Outdoors

Harden off seedlings gradually before planting outdoors. Transplant once overnight temperatures remain reliably above freezing. Space plants 20–30 cm apart, depending on variety size, in a spot that receives at least 6 hours of sunlight daily.

Soil and Watering

Snapdragons prefer fertile, well-drained soil with a slightly acidic to neutral pH (6.0–7.0). Water regularly but avoid waterlogging — consistent moisture is important, but soggy soil encourages root rot.

Feeding

Apply a balanced, low-nitrogen fertiliser every 2–3 weeks to promote strong flowering rather than excessive leafy growth.

Pinching and Deadheading

Pinch out the growing tip of young plants to encourage bushy, branching growth. Regularly remove spent flower spikes (deadheading) to stimulate continuous blooming throughout the season.

Staking

Taller varieties may need support with canes or plant supports, particularly in exposed or windy positions.

Harvesting

Harvesting Snapdragons

When to Cut

For cut flowers, harvest snapdragon spikes early in the morning when plants are well-hydrated and temperatures are cool. Select stems where the lower one-third to one-half of the blooms have opened — the upper buds will continue to open after cutting, extending the display in a vase.

How to Cut

Using clean, sharp scissors or pruning shears, cut the stem at a 45-degree angle just above a leaf node or lateral shoot. This encourages the plant to produce additional stems and prolongs the blooming season.

Post-Harvest Care

• Remove any leaves that would sit below the waterline in a vase to prevent bacterial rot.
• Place cut stems immediately into cool, clean water.
• Allow stems to condition in a cool, shaded location for 1–2 hours before arranging.
• Change vase water every 2–3 days and re-trim stems slightly to maintain water uptake.
• With proper care, snapdragons can last 7–10 days in a vase.

Encouraging More Blooms

Regular harvesting and deadheading of spent spikes signals the plant to produce more flowers, extending the display well into the season. Do not allow old flower heads to set seed if continued blooming is desired.

Common Problems

Common Problems with Snapdragons

Rust (Puccinia antirrhini)

Snapdragon rust is one of the most serious and common diseases affecting these plants. It appears as orange-brown powdery pustules on the undersides of leaves, with corresponding yellow spots on the upper surface. Improve air circulation by spacing plants adequately, avoid overhead watering, and remove and dispose of affected foliage promptly. Choose rust-resistant varieties where available.

Powdery Mildew

A white, powdery coating on leaves and stems indicates powdery mildew, typically occurring in warm days with cool nights and poor air circulation. Treat with a suitable fungicide or a diluted solution of bicarbonate of soda spray, and thin plants to improve airflow.

Botrytis (Grey Mould)

In cool, damp conditions, grey mould (Botrytis cinerea) can cause stems and flowers to collapse. Remove affected plant material immediately and avoid overhead irrigation.

Aphids

Aphids may cluster on young shoots and flower spikes, distorting growth and spreading viruses. Control with insecticidal soap, neem oil, or by encouraging natural predators such as ladybirds.

Damping Off

Seedlings may collapse at the base due to damping off fungi. Use sterile, well-draining seed compost, avoid overwatering, and ensure good ventilation around young plants.

Leggy Growth

Insufficient light causes snapdragons to become tall and weak. Ensure plants receive adequate sunlight and pinch growing tips early to promote bushy, compact growth.