How to grow snapdragons (Antirrhinum)

Where to grow snapdragons

Snapdragons will grow in most well-drained, fertile soils in full sun, either in borders or containers.

When to plant snapdragons

Sow snapdragon seeds in autumn or early spring. Sow seeds thinly on the surface of moist, peat-free seed compost, and then keep in a greenhouse or covered propagator on a sunny windowsill. Transfer seeds into individual pots when large enough to handle, and grow on in a sheltered spot or a cold frame. Plant out after all risk of frost has passed.

How to plant snapdragons

Gradually acclimatise (harden off) plants to outside conditions for around two weeks before planting out. Then water the plants thoroughly to minimise transplant shock. Prepare the soil well and remove any weeds or large stones. Dig a hole slightly larger than the size of the rootball and plant into it, backfilling the hole with soil and firming well. Water thoroughly. Plant snapdragons in threes or fives, spacing them 30cm apart, or wherever there are in gaps in the border. In pots, you can plant the rootballs closer to each other for more immediate impact.

How to care for snapdragons

Keep plants well watered until established. Support taller varieties with canes if required. Water in dry weather and water pot-grown snapdragons more often. Feed fortnightly with a high potash fertiliser such as a tomato feed – this isn't strictly necessary in garden borders but it is in pots, as there are fewer nutrients in smaller concentrations of compost. Deadhead spent blooms regularly to keep new flowers coming.

How to propagate snapdragons

Spent snapdragon flowers mature into seedheads that resemble upside-down human skulls. You can take seeds from the seedheads and sow in autumn or spring. Bear in mind that plants are unlikely to come true to type, but it's fun to see what does come up.

How to take snapdragon cuttings

Take softwood cuttings in summer, cutting 5cm lengths of stem just below a leaf node, and remove the lower leaves. Dip the bottom of the cutting in rooting hormone if you have some, but this isn't strictly necessary. Push the cuttings into seed compost, covering the pot with a plastic bag to stop the cutting drying out. Remove the plastic bag once signs of growth are evident, and pot on into individual pots when you see the roots coming out of the bottom of the pot.

Pests and diseases

Snapdragons may be affected by Antirrhinum rust. This is a fungal disease that produces dark brown spots on the undersides of the leaves. Severely affected leaves shrivel and may die. Remove leaves as soon as you see the spots, to prevent the infection taking hold. Aphids may be attracted to the leaves but are rarely present in significant numbers. It's best to let natural predators, such as ladybirds, wasps and hoverflies, manage aphid populations for you.

Snapdragon varieties to try

Snapdragon ‘Royal Bride’ – spikes of beautiful pure white flowers with a delicate fragrance. Perfect for growing in a mixed border and makes an excellent cut flower. Height x Spread: 90cm x 45cm

• Buy snapdragon ‘Royal Bride’ from Thompson & Morgan

Snapdragon 'Night and Day' – dark foliage and spikes of dark, velvety-crimson flowers with sharply contrasting silvery-white throats. H x S: 45cm x 30cm

• Buy snapdragon ‘Night and Day’ from Chiltern Seeds

Snapdragon ‘Madame Butterfly’ – mixed hybrids in a range of colours, with long-lasting double blooms. H x S: 75cm x 30cm

• Buy snapdragon ‘Madame Butterfly’ from Chiltern Seeds

Snapdragon 'Potomac Appleblossom' – tall strong stems make it perfect for cutting. H x S: 1.5m x 30cm

• Buy snapdragon ‘Potomac Appleblossom’ from Thompson & Morgan

Frequently asked questions

Does snapdragon come back every year?

Snapdragons are short-lived, tender perennials that are usually grown as annuals in the UK. It's possible to overwinter them but you'll need to dig them up and move them to a cool spot indoors, where temperatures drop no lower than 1ºC.

What do I do with Antirrhinum after flowering?

You can cut the flowerheads back to encourage another flush of blooms to develop, or let the skull-like seedheads form for a different display. Most antirrhinums are grown as annuals, so you can dig them up and compost them when you want to, or leave the plant to rot back into the soil where it is growing.