How to Grow Snapdragons: The Cool-Season Annual That Blooms Twice a Year

Learn how to grow snapdragons — one of the coolest-season, most fragrant, and most rewarding annual flowers — with complete guidance on varieties, indoor starting, planting timing, deadheading, and using them as spectacular cut flowers.

Snapdragons occupy a special place among annual flowers: they belong to the cool season rather than the heat of summer, producing their most spectacular blooms in the fresh temperatures of spring and fall. When most warm-season annuals are just getting started in June, well-timed snapdragons may already be finishing their first big flush — their spires of ruffled, fragrant blooms in an extraordinary color range among the most beautiful things in any spring garden.

The name comes from the flowers themselves — each individual bloom on the spike resembles a dragon’s mouth that opens and closes when gently squeezed on the sides. Children and adults alike find this irresistible, and a garden with well-grown snapdragons in full bloom attracts as much hands-on attention as any other flower available. Beyond charm, snapdragons are among the finest cut flowers a home gardener can grow: long-stemmed, long-lasting in the vase, powerfully fragrant, and available in colors spanning white, cream, yellow, orange, pink, rose, red, burgundy, purple, and stunning bicolors.

At Outz News Garden, Maria Walker covers the complete snapdragon growing guide — variety selection across the range of heights and colors available, starting from seed at the right time, planting at the precise cool-season window that snapdragons require, care through the growing season, and the deadheading and cut-flower harvesting approach that keeps snapdragons performing at their spectacular best. For more cool-season flowers that complement snapdragons beautifully, see our pansy guide and our cosmos guide.

Understanding Snapdragons: Cool-Season Performers

Snapdragons (Antirrhinum majus) are technically short-lived perennials native to the Mediterranean region — but in most of the US they are grown as cool-season annuals, thriving in the temperatures of spring and fall and declining in summer heat. According to Penn State Extension’s guide on annual plant hardiness, snapdragons are classified as hardy annuals — plants that can withstand spring cold snaps and fall frosts. PSU Extension notes that snapdragons may even survive mild winters in some regions, particularly as USDA hardiness zones continue to shift slightly warmer.

This cool-season preference defines everything about how snapdragons are grown:

• They are planted earlier in spring than warm-season annuals — before the last frost date, not after it
• They perform best when daytime temperatures stay below 80°F — hot summer weather causes bloom decline and often plant decline
• They experience a second, often spectacular bloom period in fall as temperatures cool again
• In mild-winter climates (Zone 8 and warmer), they can be grown as winter and early spring flowers planted in fall

University of Minnesota Extension’s May garden checklist confirms: plant cool-season flowers in early to mid-May, like snapdragons, violas and pansies, and sweet alyssum — these plants can handle light frosts. This frost-tolerance in the planting window is what makes snapdragons so valuable for early spring color, weeks before any warm-season annual can go outside.

Snapdragon Varieties: Height Classes and Color Range

Snapdragons are available in three height classes that determine their most appropriate garden uses — choosing the right height for each application is one of the most impactful variety decisions:

Dwarf Snapdragons (6 to 10 inches)

Compact, mounding plants that work beautifully at the front of borders, in containers, and as mass plantings for spring color. They rarely need staking and produce an abundance of small, densely spaced blooms:

• Floral Showers series: outstanding heat and cold tolerance; one of the most widely trialed dwarf series; excellent for containers and bedding
• Montego series: early-blooming; wide color range; compact and self-branching
• Snapshot series: uniform, compact habit; excellent garden performance from spring through fall

Intermediate Snapdragons (12 to 24 inches)

The most versatile height class — tall enough for visual impact in the border but compact enough to avoid staking in most situations. This is the range most garden center transplants occupy:

• Animation series: excellent disease resistance; strong stems; good heat tolerance for the class
• Sonnet series: outstanding garden performance; wide color availability; one of the best intermediate series for home gardens
• Twinny series: double flowers (two layers of ruffled petals) in soft, pastel colors; very different texture from standard single snapdragons

Tall Snapdragons (30 to 48 inches)

The premier cut flower class — long stems ideal for vase arrangements, with the most dramatic presence in the back of the border. According to University of Minnesota Extension’s cut flower research, snapdragon stems are typically around 3 feet tall and are easy to harvest and process because of their long, straight stems — though they are susceptible to gravitropism (bending toward light) if not supported or protected from wind.

• Rocket series: one of the most widely grown tall snapdragons; excellent heat tolerance for the class; strong, upright stems; all-color and single-color packets available
• Madame Butterfly series: open-faced, azalea-like double flowers rather than the traditional “closed-mouth” snapdragon form; stunning and unusual; excellent as a fresh and dried flower
• Chantilly series: open-face flowers; softer, more graceful appearance than the traditional form; outstanding in bouquets — University of Minnesota Extension’s cut flower trial specifically identified ‘Chantilly Light Salmon’ as producing an orange-salmon ombré appearance that fits into a variety of spring and summer bouquets

Starting Snapdragons from Seed Indoors

Snapdragons are among the flowers that genuinely benefit from indoor starting — their long growing period before bloom (10 to 16 weeks from seed) makes an early indoor start essential for spring bloom in most US climates. According to University of Minnesota Extension’s seed starting guide, snapdragons are specifically recommended for starting in early March in Minnesota — roughly 8 to 10 weeks before outdoor planting.

Seed Starting Timeline

• When to start: 10 to 12 weeks before your outdoor transplanting date (which itself is 2 to 4 weeks before last frost). Most US gardeners start snapdragons in late January through early March.
• Sowing technique: snapdragon seeds are very fine — among the smallest of common annual flower seeds. Press seeds onto the surface of moist seed-starting mix without covering; snapdragon seeds require light to germinate. Simply press them gently onto the medium surface and mist lightly.
• Germination conditions: 65 to 75°F soil temperature; keep consistently moist; cover tray with a clear dome or plastic wrap to maintain humidity. Germination occurs in 10 to 14 days.
• After germination: remove the dome and move immediately under grow lights — 14 to 16 hours daily, lights 3 to 4 inches above seedlings. Cool temperatures (55 to 65°F nights, 65 to 70°F days) produce the stockiest, most flower-ready transplants.
• Pinching: when seedlings reach 4 to 5 inches tall, pinch out the growing tip — this encourages branching and produces a fuller, more productive plant. Unpinched snapdragons tend to produce a single main spike; pinched plants produce multiple spikes per plant.

Purchasing Transplants

Garden centers typically offer a good selection of snapdragon transplants in spring. Penn State Extension’s container gardening guide notes that snapdragons are a natural choice for spring containers — when purchasing, choose compact, dark-green, well-branched plants that are not yet in full bloom. Plants in bud or early bloom establish and perform better than plants already at peak bloom at purchase.

When and Where to Plant Outdoors

Timing: Earlier Than Most Annuals

Snapdragons’ cold-hardiness is their most practically valuable characteristic for gardeners eager for early spring color. University of Minnesota Extension confirms snapdragons can handle light frosts — this means they go into the ground weeks before the last frost date that dictates when warm-season annuals like marigolds and zinnias can be planted.

• Northern US (Zone 5 to 6): transplant outdoors in late April to mid-May, 2 to 4 weeks before last frost
• Mid-Atlantic and Midwest (Zone 6 to 7): late March to mid-April
• South (Zone 7 to 9): September through November for fall/winter/spring blooms — snapdragons shine as cool-season plants in regions where summers are too hot for them
• Harden off transplants over 5 to 7 days before outdoor placement — even frost-tolerant plants need gradual adjustment from indoor growing conditions to outdoor light and temperature variability

Site Selection

• Full sun to partial shade: snapdragons bloom most prolifically in 6 or more hours of direct sun. In very hot climates, some afternoon shade extends the spring blooming period by reducing heat stress. In cool-summer climates (Pacific Northwest, high elevations), full sun all day is ideal.
• Well-draining soil: snapdragons are susceptible to root rot in waterlogged conditions. Raised beds and naturally well-draining sites suit them perfectly.
• Good air circulation: important for preventing rust and other fungal diseases to which snapdragons are susceptible — avoid planting in low-air-flow corners or tightly against walls
• Soil pH 6.0 to 7.0

Planting and Spacing

• Space dwarf varieties 6 to 8 inches apart
• Space intermediate varieties 10 to 12 inches apart
• Space tall varieties 12 to 18 inches apart — UMN Extension’s cut flower research notes that tall snapdragons benefit from netting or support that keeps their long stems growing straight and upright
• Plant at the same depth as in the container
• Water with a dilute balanced fertilizer solution at planting to support establishment
• Mulch around plants with 2 inches of shredded bark or shredded leaves — conserves moisture, moderates soil temperature, and suppresses weeds

Ongoing Care: Water, Fertilizer, and Support

Watering

Snapdragons prefer consistent moisture — allow the top inch of soil to dry before watering, then water thoroughly. University of Maryland Extension’s annual care guide recommends avoiding overhead watering (sprinklers wetting flowers and foliage) — water from sprinklers makes plants susceptible to diseases. Water at the soil level to keep foliage dry, particularly important for snapdragons which are susceptible to rust fungus on wet foliage.

Fertilizing

Snapdragons are moderate feeders. Apply a balanced slow-release fertilizer at planting time, then supplement with a dilute liquid balanced fertilizer every 3 to 4 weeks through the growing season. University of Maryland Extension notes that if you add organic matter on a regular basis, your plants may require little additional fertilizer — a well-composted, organically rich soil reduces the need for supplemental feeding considerably.

Supporting Tall Varieties

University of Minnesota Extension’s cut flower guide is specific about supporting tall snapdragons: ensure snapdragons are supported by netting or protected from strong winds and rain, as the blooms can become unusable if stems begin to grow at different angles. Low tunnels and other coverings can reduce wind damage. For home gardens, practical support options include:

• Grow-through wire grids or peony rings installed at planting time
• Bamboo stakes and soft twine for individual stems of the tallest varieties
• Planting in groups that provide mutual support in sheltered locations

Deadheading and Pinching for Extended Bloom

Deadheading — removing spent flower spikes — is essential for keeping snapdragons in continuous active bloom rather than setting seed and declining. Unlike some annuals where only the spent flower head is removed, snapdragons are best deadheaded by cutting the entire spike back to a lateral shoot or leaf node lower on the stem:

• When the bottom third of a spike has spent flowers and the top two-thirds are still in bloom, cut the entire spike after the last flower fades
• Cut back to the first side shoot or set of healthy leaves — new flowering shoots emerge from these lateral points
• The more consistently you deadhead, the more spikes the plant produces in response
• For cut flowers: harvest stems before all flowers on the spike have opened — cutting at the bud stage maximizes vase life and automatically deadheads the plant for future spikes

Managing Summer Decline

When summer heat consistently exceeds 85 to 90°F, snapdragons typically stop blooming and may appear to decline — this is not death, but heat-induced dormancy. Two management approaches:

• Cut back hard and wait: cut all stems back by half in midsummer, reduce watering, and allow the plant to rest. When cooler fall temperatures arrive (typically September), snapdragons often flush with a spectacular second bloom that rivals or exceeds the spring performance.
• Replace with summer annuals: in very hot climates where the summer gap is long, remove snapdragons in June, plant summer annuals in their place, and re-plant snapdragons in late August or September for fall bloom.

Snapdragons as Cut Flowers

University of Minnesota Extension’s cut flower research specifically evaluated snapdragons for their cut flower performance, finding them easy to harvest and process with long, straight stems — though noting their susceptibility to bending if not handled carefully. For the best cut snapdragon performance:

• Harvest in the morning when stems are fully turgid (water-filled) — cut when the bottom one-third to one-half of the spike’s flowers are open, with the rest still in bud
• Cut at an angle and immediately place in a bucket of cool water — snapdragon stems seal rapidly when exposed to air, so the transition from cut to water must be quick
• Strip all foliage that would be below the waterline in the vase — submerged foliage rots and reduces water quality
• Vase life: 7 to 14 days with fresh water every 2 to 3 days and stem recutting; one of the longest-lasting cut flowers available from the home garden
• Fragrance: many snapdragon varieties — particularly heirlooms and some intermediate types — have significant, pleasant fragrance; this is one of the most fragrant cut flowers available for home garden production

Common Snapdragon Problems

• Rust (orange powdery pustules on leaves and stems): the most common and most serious snapdragon disease — a fungal infection that spreads rapidly in cool, moist conditions with poor air circulation. Control: choose rust-resistant varieties (labeled as such on seed packets); improve plant spacing for airflow; avoid overhead watering; apply a fungicide labeled for rust on ornamentals at first sign of infection. Remove and dispose of heavily infected plants away from the garden.
• Botrytis (gray mold on flowers and stems): affects plants in cool, wet, densely planted conditions. Improve air circulation; remove spent flowers promptly; avoid wetting foliage.
• Aphids: particularly common on new growth in spring. Knock off with a strong water spray; apply insecticidal soap for heavier infestations. Lady beetles and their larvae typically manage aphid populations on snapdragons naturally.
• Failure to bloom in summer: heat stress — normal and expected behavior. Cut back and wait for fall, or replace with summer-appropriate annuals and replant snapdragons in late summer.
• Leggy, floppy growth: insufficient light or failure to pinch when young. Pinch seedlings at 4 to 5 inches; ensure 6+ hours of direct sun; provide support for tall varieties.

Quick-Reference Snapdragon Growing Guide

• Cool-season annual — plant 2 to 4 weeks BEFORE last frost, not after
• Start seeds indoors 10 to 12 weeks early — press on surface of mix, needs light to germinate
• Pinch seedlings at 4 to 5 inches — produces multiple spikes, not just one
• Full sun preferred — some afternoon shade extends spring season in hot climates
• Water at soil level — wet foliage promotes rust fungus
• Support tall varieties — prevents gravitropism (stem bending)
• Deadhead entire spikes back to a side shoot for continuous bloom
• Cut back in summer heat — they’ll rebound with a gorgeous fall flush
• Outstanding cut flower — harvest at one-third to one-half open for 7 to 14 days of vase life

Growing snapdragons successfully means embracing their cool-season rhythm — planting early, enjoying the spectacular spring bloom, managing through summer heat, and welcoming the fall rebound that rewards patient gardeners with a second round of color when most annuals are finishing. No other common annual provides quite the same combination of early-season impact, extraordinary fragrance, wide color range, and cut flower quality that snapdragons deliver at their spring peak.

Plant them early, pinch them young, support the tall ones, and deadhead them consistently. And discover, as every snapdragon grower eventually does, that the satisfaction of a fully loaded snapdragon spike — fragrant, colorful, buzzing with pollinators on a cool May morning — is one of the most genuinely beautiful things a garden can offer.

Share your snapdragon variety favorites and cut flower arrangements in the comments! And for more cool-season flowers that bloom alongside snapdragons in the spring garden, see our marigold guide for the warm-season flowers that follow, and our pollinator garden guide for the companion planting combinations that attract the most wildlife.

👉 Read Next: How to Start Seeds Indoors — The Complete Beginner’s Guide

Maria

Maria Walker is a certified horticulturist and gardening specialist with over 15 years of hands-on experience in plant care, garden design, and sustainable growing practices.
She holds a Bachelor’s degree in Horticulture Science and a Master’s degree in Sustainable Agriculture — and has spent her career helping people of all skill levels create beautiful, thriving gardens.
Maria launched Outz News Garden with one simple mission: to make gardening accessible and inspiring for everyone, from first-time planters to seasoned green thumbs.