How to grow snapdragons

Val Bourne / 15 February 2021

Snapdragons, or antirrhinums, flower all summer long and make excellent cut flowers. Find out how to sow snapdragon seeds, as well the best varieties for cut flowers and container growing.



Snapdragons, or antirrhinums, have been a cottage garden favourite for many a year, because their upright, bee-pleasing flowers give months of flower.

If you deadhead snapdragons to prevent seeds from being formed, you’ll likely to have flowering spikes from April through to October.

The sturdy stems add a vertical presence and there’s a surprising amount of choice in a variety of colours, from elegantly simple cut-flower varieties, to compact dark-leaved patio plants, to frilly double.

Some of the paler flowered snapdragon flowers are also scented, so at the moment they’re riding the crest of a wave. You can go for inexpensive mixtures that provide lots of seeds per packets, or highly-bred F1 varieties or cutting-raised plants. Although always listed as annuals, many antirrhinums will overwinter in well-drained sunny positions.

Growing snapdragons from seed

Sowing

It’s best to sow antirrhinums, or snapdragons, in spring, once the weather begins to warm up. If the compost is cool and moist, antirrhinum seedlings are prone to damping off, caused by Pythium and Phytophthora fungi.

Fungal spores are both more likely to be found in Water-butt water than chlorinated tap water so it’s best to water all seedlings with tap water. Use a clean can with a fine rose, one that delivers a limited amount of water. Allow the can of water to stand for a couple of hours. This will allow chlorine to escape and the water should warm up.

Wait for warmer spring days and use clean containers and seed-sowing compost. Fill small seed trays and water them well (before sowing) and allow the trays to drain. Put the seeds in the palm of your hand and sprinkle the fine seeds as thinly as you can, using half a packet if there are plenty. Do not cover the seeds.

Damping off usually occurs within 14 days of germination. It’s more likely to happen in cool conditions, so give your seedlings an ambient temperature that ranges between 18 - 24C or 66 - 75 F.

How long do snapdragons take to germinate?

Germination takes on average 21 days. Prick out into modular trays with 24 cells, once your seedlings have developed their first true leaves. Keep the seedlings on the drier side and out of full sun. Fleece the seedlings on cold nights.

Pinch back by half when your young plants have developed 4-6 leaves, to create more side branches.

Give your garden a makeover and save money at the same time with a special Thompson and Morgan offer of 10% off.

Growing snapdragons in containers

Patio antirrhinums, designed to be grown in containers, are compact, eye-catching and long-flowering. They also have to have handsome foliage.

Antirrhinum ‘Mini Cherry Cola’

Thompson & Morgan’s breeders have produced a real winner with almost-black foliage and dusky cherry-pink flowers. The flowers are almost penstemon-like, so they’re accessible to a whole range of pollinators. Most antirrhinums have a bottom lip that need a weighty bumblebee to press it down. There’s a glimmer of white at the throat, adding an extra highlight, and ‘Mini Cherry Cola’ (exclusively from T&M) can be grown from seed and, at 500 seeds per packet, there’ll be plenty of foot-high plants to bed out in the borders as well. Modern plant breeding has selected for rust-resistance.

Antirrhinum ‘Bronze Dragon’

Another patio snapdragon variety raised by Thompson & Morgan, ‘Bronze Dragin’ has pale-mauve and white bi-coloured flowers, highlighted by very dark foliage with bronzed overtones. You could a grow it in a hot spot, with silver-leaved plants, or in a container. 30cm/ 12in

Good antirrhinum varieties

Antirrhinum ‘Night and Day’

Well-named because the sophisticated flowers are a combination of velvety dark-red and clean-cut vory-white. This old seed variety is a cut-flower and bumblebee favourite. Fred Astaire on legs. 45cm. 18in

Antirrhinum ‘Black Prince’

Another old, stable variety with slightly upward-facing sultry black-red flowers emerging from sooty buds. The foliage is dark-green at first, but turns black in hot weather. 45cm. 18in

Antirrhinum ‘Axiom Series Mixed’ F1 Hybrid

If you want a tall antirrhinum, to cut or grow, this F1 hybrid mixture of seven summery colours is for you. The seeds are expensive and there are not many of them, but hybrid vigour will ensure excellent germination. Each tall lower spikes contains far more snapdragon flowers. It’s considered the best. 90cm/ 36in

Antirrhinum ‘Circus Clowns’

A traditional snapdragon with bi-coloured flowers, often marked in white or deep-pink,. This jaunty mixture will cheer you up and it offers good value. 45cm/ 18in

Antirrhinum ‘Magic Carpet’

A shorter, value-for-money snapdragon in a wide range of sunset oranges, yellows and pinks. Best at the front of a border. 15cm/ 6in

Antirrhinum ‘Frosted Flames’

This snapdragon comes in a mixture of cherry-pinks, yellows and sunset orange-pinks, but the green foliage is margined in white, hence the name frosted. 45cm/ 18in

Antirrhinum ‘Candy Canes Mixed’

This flamboyant mixture of clear colours, including pallid-yellow, various pinks, vermilion, soft-white and deep-red, will add a splash of colour in vase or garden. The flowers are highly fragrant and the foliage is very healthy. Available as plugs to grow on. 45cm/ 18in

Growing snapdragons for cutting gardens

The best cutting varieties have long-stemmed flowers in individual colours.

The optimum time to cut snapdragons is when the spikes have 30% of the flowers open, or when between 5 -7 florets are open.

Stand the stems in warm water ( 21-25C) overnight and use a cut-flower food is possible. The Axiom F1 hybrids last a long time in water, up to 10 days. Use a clean vase and fill with tap water.

Cut about 5cm off the end of the stem and strip the bottom leaves off and sear the stem ends in boiling water for 10 seconds, before arranging.

Frilly double-flowered antirrhinums like ‘Madame Butterfly’ have longer lasting flowers, in the garden and in the vase. They don’t have a traditional snapdragon profile, but they still look handsome in the garden.

Antirrhinum ‘Royal Bride’

Fragrant white flowers, with a hint of lemon and lime, held above good green foliage. Probably best in bright shade, because off-whites look anaemic in full sun. You’ll get lots of flowers per stem from May until late. Sold as plug plants and seeds. Up to 90cm/ 3ft

Antirrhinum ‘Lucky Lips’

A moody mixture of cool purple-pink and white, with red overtones, this elegant snapdragon slots into summer borders really well. It will also look good in a cutting garden whether bedded out in lines, or interwoven through roses and perennials. 60cm/ 24ins

Antirrhinum ‘Purple Twist’ F1 Hybrid

A bit of a Marmite variety with white flowers randomly steaked and splashed in raspberry red. Every flower’s different indicating a jumping gene. Up to 90cm/ 3 ft

Antirrhinum ‘Rembrandt’

A mixture of burnt-orange and warm-yellow two-tone flowers held on shorter stems. Despite being short, it’s a cut flower favourite. 30cm/ 1ft

Antirrhinum Madame Butterfly F1

This open-flowered double form is widely available as seeds or plug plants. The open frilly flowers are not typically snapdragon and they’re described as azalea-flowered or godetia-like. These open-flowered varieties don’t mind hot sunshine and they cut well. 75cm/ 30in

Are snapdragons perennials?

Snapdragons are short-lived perennials that are often sold and grown as annuals, but they can overwinter in the UK in a well-drained, sunny positions.

Do snapdragons come up every year?

Snapdragons often self-seed, so even if your plant dies over winter you might still get snapdragons the following year, although they may not look like the parent plant. If your plant is an F1 variety the seeds might be sterile.

How long does it take to grow snapdragons from seed?

Snapdragon seeds germinate in about 21 days, and will be flowering from two to three months after sowing.

The opinions expressed are those of the author and are not held by Saga unless specifically stated.

The material is for general information only and does not constitute investment, tax, legal, medical or other form of advice. You should not rely on this information to make (or refrain from making) any decisions. Always obtain independent, professional advice for your own particular situation.