How-to Guide
How to Grow Snapdragons
The short answer
Snapdragons are cool-season annuals that tolerate light frost — hardy to roughly 15°F according to Arkansas Extension — so plant them in early spring while the soil is still cool, 2 to 3 weeks before frost-tender annuals go out (Iowa State Extension). Give them full sun and well-drained soil.
To keep them blooming, remove old flower spikes: as each raceme lengthens and fades, cut it off entirely so the plant sends up new stems. Cut taller varieties back to about 6 inches after flowering and they will rebloom (Clemson Extension). In mild-winter regions, snapdragons are also planted in fall alongside pansies.
When to Plant (Earlier Than You Think)
Snapdragons come from the southern Mediterranean and are built for cool weather. Arkansas Extension rates them cold-hardy to about 15°F and tolerant of light frost, which means early-spring planting is safe while soil is still cool.
Iowa State Extension groups them with frost-tolerant annuals that can go out 2 to 3 weeks earlier than tender bedding plants. Transplant young plants so roots establish before flowering starts.
✔ In mild-winter regions (Clemson notes zone 8 plants living nearly 3 years), plant snapdragons in fall as the weather cools for bloom through fall and again the following spring — the same slot as pansies.
Sun and Soil
Full sun and well-drained soil are the baseline (Arkansas Extension); Clemson allows full to part sun. Amend the bed with organic matter, and water regularly — including through fall and winter for fall-planted snaps (Clemson Extension).
Pick Your Height Class
- Dwarf: 6-10 inches (e.g., Floral Showers, Snapshot) — low borders and containers.
- Medium: 12-22 inches (e.g., Candy Tops, Liberty Classic, Snaptastic) — beds and mixed borders.
- Tall: 24-60 inches (e.g., Madame Butterfly 24-36", Rocket to 36", Potomac to 60") — cut flowers; tall varieties need support.
- Trailing: about 6 inches tall, trailing to 12 inches (e.g., Candy Showers) — baskets and wall tops. (Heights per Clemson Extension.)
Deadheading and Cutting Back
Snapdragon spikes (racemes) keep lengthening as lower flowers fade. Arkansas Extension's advice: at some point you simply cut the whole spike off to force new flower stems. Remove old flowers so plants don't spend energy on seed (Clemson Extension).
After a flush finishes, cut taller varieties back to about 6 inches and feed with an all-purpose fertilizer; new flowering stems follow (Clemson Extension). Summer heat stalls bloom — cut back, keep watered, and expect a strong return in cool fall weather.
Problems
- Bloom shutdown in high summer heat — a scheduling issue, not a disease; plan snapdragons as spring and fall color.
- Tall varieties flop without staking or netting.
- Overly wet soil causes root problems — drainage is non-negotiable.
Sources
Reviewed 2026-07-18. We cite university Extension, government, and established horticultural sources — and never invent pesticide rates or dangerous treatments.
- University of Arkansas Cooperative Extension — Snapdragon (Plant of the Week) — Cool-season Mediterranean annual; cold hardy to about 15°F, tolerates light frost for early spring planting; full sun, well-drained soil; remove lengthening racemes to force new flower stems; fall planting with pansies in mild regions
- Clemson University HGIC — Snapdragons for Fall Blooms — Height classes with cultivar figures (dwarf 6-10", medium 12-22", tall 24-60", trailing); fall planting for fall-plus-spring bloom; cut tall varieties to 6 inches after flowering; full to part sun, organic-amended well-drained soil
- Iowa State University Extension — Growing Cool Season Annuals — Snapdragons are frost-tolerant annuals that can be planted 2 to 3 weeks earlier than tender annuals