Growing Snapdragons
- Jane Westoby
- Apr 18, 2024
- 6 min read
Updated: Apr 23
How to Grow and Harvest Snapdragons for Continuous Blooms
Snapdragons are the ultimate flower grower’s dream—incredibly productive, available in a vast array of colours, and one of the best cut-and-come-again crops for the cutting garden.
From elegant wedding whites to deep velvet purples, soft pastels, and striking bicolours, there’s a snapdragon variety for every occasion.
If you choose the right varieties, you can grow snapdragons from early spring right through to autumn, and in some cases, even overwinter them for early blooms. As a flower farmer, investing in high-yielding, long-lasting crops is essential, and snapdragons will keep producing more stems the more you cut them. With the right care, they’ll be one of your most profitable and rewarding crops.
Best Snapdragons for Cutting
Not all snapdragons are created equal when it comes to cutting. Choose tall varieties designed for the cut flower market, rather than compact bedding types.
Top varieties for cutting:
Potomac, Doubleshot, and Maryland – Excellent for long, straight stems.
Madame Butterfly & Sn – Versatile and blooms across all growing groups.
Avoid dwarf bedding types like Twinny—beautiful, but with shorter stems more suited to garden borders.
Understanding Snapdragon Groups
Snapdragons are classified into numbered groups based on their ideal growing and flowering conditions. Choosing the right variety for the right season will ensure strong stems and high-quality blooms.
Group 4 (Mid-Summer Bloomers): Opus, Potomac, Maryland – Tolerate high temperatures and lots of direct sun.
Winter & Spring Bloomers: Snapstar – Specifically bred to bloom in cooler temperatures and lower light levels.
All-Season Performer: Madame Butterfly – Covers all four groups, making it a reliable choice for flower farmers.
How to Sow Snapdragon Seeds
Snapdragon seeds are tiny, but with careful handling, they’re easy to germinate and grow into strong, healthy plants.
Use a high-quality, free-draining potting mix. Fill seed trays or small pots, pressing the soil down gently to remove air pockets.
Pre-moisten the soil before sowing—snapdragon seeds are so small they can be washed away if watered from above.
Sow thinly and evenly over the surface of the compost. If using soil blocks, a toothpick can help place the seeds accurately.
Cover lightly with vermiculite and mist gently to settle the seeds.
Place under a humidity dome or cover to retain moisture and put onto a heat mat for faster germination.
Move to a cooler, well-lit space as soon as they germinate (usually within a week).
Preventing Damping Off
Snapdragon seedlings can be prone to damping off (a fungal disease that kills young plants). To reduce risk:
Use plenty of airflow—a small fan or open greenhouse vents on mild days.
Avoid overwatering—let the soil dry out slightly between waterings.
Harden off seedlings by placing them outside for a few hours on mild days.
Planting Out & Growing Snapdragons
Snapdragons take 100–120 days from sowing to flowering, though overwintered seedlings will bloom much earlier in the season.
Autumn-sown seedlings will flower in late winter to early spring.
Spring-sown snapdragons will bloom midsummer through to autumn.
When to Plant Out
Snapdragons can be planted out when they are still small. They’ll establish their root system beneath the soil, ready to take off when the weather warms.
For early spring blooms, plant in autumn or late winter with some frost protection.
For summer and autumn flowers, plant in early spring.
Snapdragons can tolerate cold but not prolonged frost or snow—so a low tunnel or fleece covering may be needed in harsh conditions.
Growing Conditions
Light: Full sun to partial shade (at least 6 hours of sunlight per day).
Water: Keep soil consistently moist but not waterlogged. Water at the base to prevent fungal disease.
Fertiliser:
Apply a balanced feed every 4–6 weeks during active growth.
Once buds appear, switch to a high-potash feed (like tomato fertiliser) to encourage strong flower production.
Pinching for More Blooms
Snapdragons benefit from pinching to encourage more branching and higher yield.
Pinch plants when they have 2–3 sets of leaves and are a few inches tall.
If you prefer longer central stems, skip pinching—cutting the first flower stalk will encourage later regrowth as bushier stems.
Harvesting & Conditioning Snapdragons for the Longest Vase Life
Cut deep into the plant, rather than deadheading—this encourages longer stems and stronger regrowth.
Harvest when around 1/3 of the flowers are open. Cutting too early results in poor colour development and smaller blooms.
Condition stems properly:
Snapdragons are geotropic—they bend towards gravity if laid at an angle. Store them upright in deep water.
Leave in a cool, dark place for a few hours before arranging.
Snapdragons are one of the most rewarding cut flowers you can grow—highly productive, long-lasting, and available in colours to suit every bouquet. By choosing the right varieties and caring for them correctly, you can enjoy a continuous harvest from early spring through to late autumn.
Which Snapdragons to grow
For cutting choose tall varieties such as the Potomac, Doubleshot & Maryland series, rather than dwarf bedding. Twinny is beautiful for sure but stem length will be much shorter so save those for the garden.
Most snapdragon varieties are classified into numbered groups which correspond with certain growing and harvesting periods which will give the best results. Choosing your snapdragons by their flowering period is the best way to get the best blooms when you want them. Sowing, growing & harvesting at the appropriate times will ensure good stems length and bloom quality.
Some varieties such as Opus, Potomac & Maryland can be grown for mid summer harvests (Group 4) as they can tolerate high temperatures and lots of direct sunlight, whereas Snapstar has been specifically bred to be grown throughout winter and spring time when light levels and temperatures are lower. If grown throughout midsummer they may stop blooming as its too hot for them. Madame Butterfly goes across all four groups so is the perfect candidate for flower farming.
How to Sow Snapdragon Seeds
Start by selecting a high-quality potting mix that drains well. Fill seed trays or small pots with the soil mix, lightly pressing it down to remove air pockets.
Moisten the soil before sowing the seeds. This is important as the seeds are so tiny they can get washed away with watering before they even germinate!
Scatter the snapdragon seeds evenly and very very thinly over the compost or you may choose to use soil blocks and a toothpick. A bit fiddly but will save time later on when it comes to pricking out. It will also ensure that you don't oversow!
Cover with a thin layer of vermiculite and mist the surface gently to settle the seeds. I usually pop mine under a cover to keep the moisture levels high and then onto a heat mat.
They take around a week to germinate and are then moved to slightly cooler conditions to grow on with plenty of light and airflow. especially in autumn when they are more prone to damping off. This can be prevented by using a fan, leaving the greenhouse door and window open, or simply popping them outside for a few hours on a nice day, and letting the soil dry out a little between waterings.
Planting out and growing Snapdragons
Snapdragons take around 100 - 120 days to flower but will grow much slower over winter. Seedlings started in Autumn will flower in late Winter/ Early spring time and those sowed in Spring will flower midsummer and Autumn.
Snaps can be planted out quite early when they are still quite small, they will build up their roots under the soil ready for when the weather warms. They are best planted out in autumn to late winter with a little protection just from snow and ice but they will withstand cold temperatures.
They thrive in full sun to partial shade. Ensure they receive at least 6 hours of sunlight daily for optimal growth and abundant blooms. Keep the soil consistently moist but not waterlogged. Water at the base of the plants to avoid wetting the foliage, which can lead to fungal diseases.
Feed snapdragons with a balanced fertilizer every 4-6 weeks during the growing season to support healthy growth and prolific flowering.
For a bushy plant with lots of blooms plants can be pinched when they have grown 2-3 sets of leaves and are a couple of inches tall. However if you prefer a large central stalk then don't pinch out. Once this is cut the re growth will then form shorter bushier stems.
Cutting and Conditioning Snapdragons
When cutting ensure you cut deep rather than deadheading, this will promote longer stems. Harvest when around 1/3 of the flowers are open - no sooner as premature harvesting can lead to poor colour development and reduced flower size as flowers continue to open.
Stems should conditioned in a cool dark place in lots of water and should be kept upright as they are geotrophic and will curve upwards if laid at any angle
For more information on growing Hardy Annuals check out our blog Growing Cool Flowers
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