Growing Snapdragons: When to Plant, Care and Reblooming

Snapdragons (Antirrhinum majus) are cool-season flowers: they bloom best in spring and fall and tend to stall in summer heat. Most problems come from treating them as summer annuals. This guide to growing snapdragons covers what they are, whether they come back, hardiness, when to plant, light, soil and water, deadheading for more blooms, varieties, the skull-shaped seed pods and pet safety. It follows NC State, UF/IFAS, Missouri Botanical Garden, the RHS and the ASPCA.

Sources: Missouri Botanical Garden; NC State Extension; UF/IFAS EP549; RHS.

What Is a Snapdragon?

Antirrhinum majus is in the plantain family, Plantaginaceae, and is native to southwestern Europe (NC State; Missouri Botanical Garden). MOBOT explains that the genus name comes from the Greek anti, like, and rhis, nose or snout, after the dragon’s-snout look of the closed, two-lipped flowers. The RHS describes the wild species as a short-lived perennial, often woody at the base, with stems up to 2 m, lance-shaped leaves up to 7 cm and fragrant pink or purple flowers; garden cultivars are much shorter.

The UF/IFAS publication “Planting and Propagation of Snapdragons in Florida” (EP549) says only snapdragons in the Antirrhinum section have been domesticated, that growing them as garden plants dates back to the Roman Empire, and that Romans and Greeks believed they protected against witchcraft and illness. During the Renaissance they were thought to bring charisma, glory, honor and social status.

Annual or Perennial?

Both. NC State calls snapdragon a short-lived tender perennial grown as an annual. MOBOT says it is winter hardy in USDA Zones 7 to 10 but usually grown as an annual in St. Louis (Zone 6). Well-mulched plants in protected spots may overwinter there, and cuttings can be taken in fall, but MOBOT notes that snapdragons are inexpensive and perhaps best bought again each spring. Even where they survive, they are short-lived.

Hardiness Zones

NC State and MOBOT both give USDA Zones 7 to 10. The RHS rates the species H2: tolerant of low temperatures but not surviving being frozen. MOBOT adds that south of Zone 7, snapdragons are often planted in fall, like pansies, where they survive winter and bloom as long as temperatures stay above freezing. In Zone 6 and colder, grow them as annuals.

When to Plant

• Cold-winter areas: MOBOT says to start seeds indoors 6 to 10 weeks before the last frost date, or buy starter plants, and set them out after the last frost.
• Mild-winter areas: plant in fall. UF/IFAS EP549 says the ideal planting window in Florida runs from late fall through early spring, and that high temperatures in late spring, summer and early fall stunt growth and limit blooming.

In UF/IFAS’s central Florida container trial (EP652), snapdragons were ideal for cool-season planting from fall through early spring. Cutting the stem back to 5 inches stimulated more flower spikes, and blooming continued until June 2024, when rising temperatures began to impede development.

Light

MOBOT lists full sun; NC State lists full to part sun. In hot regions, some afternoon shade can extend flowering. Tall plants may need staking when young (NC State; MOBOT). MOBOT recommends pinching the stem tips of young plants to make them bushier and less leggy.

Soil, Water and Feeding

NC State and MOBOT both call for moist, rich, well-drained soil. UF’s container trial (EP652) adds rich, well-drained, moist soil with a neutral pH. Avoid overhead watering (NC State; MOBOT); water at the base instead, and space plants for airflow.

Diseases: NC State lists significant susceptibility to rust, plus mold, fungal leaf spots, downy mildew, wilt and root rots. MOBOT advises growing snapdragons in another part of the garden the following year if rust appears, and always buying fungus-resistant plants or seeds. The RHS also lists antirrhinum rust and powdery mildews, and aphids as a pest.

Feeding: MOBOT suggests cutting plants back hard and fertilizing if flowering slows after the first flush. A balanced flower fertilizer at the label rate is a reasonable choice; see our synthetic vs organic fertilizer guide.

Deadheading for More Blooms

The RHS says deadheading will prolong the flowering period, and MOBOT says to deadhead spent flowers to prolong bloom.

1. When most flowers on a spike have faded, follow the stem down to a healthy leaf or side shoot.
2. Cut just above it with clean, sharp pruners.
3. Clear fallen petals and trimmings to reduce disease.
4. If the whole plant slows after the first flush, cut it back hard and fertilize (MOBOT). In UF’s trial, cutting stems back to 5 inches produced more spikes (EP652).

Colors and Varieties

MOBOT says cultivars are grouped by height: dwarf (8 to 12 inches) for beds, edging, window boxes and containers; intermediate (12 to 24 inches) for bedding and mixed borders; and tall (24 to 36 inches) for borders and cutting gardens. Colors include white, yellow, pink, red, orange, peach and purple, plus bicolors (MOBOT). UF/IFAS EP549 names ‘Floral Showers Mix’, ‘Aromas’, ‘Snapshot’ and ‘Twinny Mix’ as performing well in Florida, especially in warm conditions, and notes most commercial varieties aren’t marketed as heat-tolerant.

Why Seed Pods Look Like Skulls

After the flowers drop, the seed capsules dry and split open, leaving a small brown pod with openings that look like eye sockets and a mouth. Leave a few spikes un-deadheaded at the end of the season if you want to see them or collect seed.

In the Victorian language of flowers, Kate Greenaway’s Language of Flowers (1884) gives snapdragon the meaning “Presumption.”

Are Snapdragons Safe for Pets?

Yes. The ASPCA lists the common snapdragon, Antirrhinum majus, as non-toxic to dogs, cats and horses, and NC State tags it non-toxic for all three. NC State adds that the flowers are edible but bitter, best used as a garnish. Eating any plant can still cause mild stomach upset in pets. For more options, see our cat-safe plants list.

For more garden flowers, see our guides to daisies and peonies.

Frequently Asked Questions

Do snapdragons come back every year?

In USDA Zones 7 to 10 they can, as short-lived perennials (MOBOT; NC State). In colder zones they are grown as annuals.

When is the best time to plant snapdragons?

After the last frost in cold-winter areas, with seeds started indoors 6 to 10 weeks earlier (MOBOT). In mild climates like Florida, late fall through early spring (UF/IFAS).

How tall do snapdragons grow?

Dwarf types reach 8 to 12 inches, intermediate 12 to 24 inches and tall 24 to 36 inches (MOBOT).

How do you get snapdragons to bloom again?

Deadhead spent spikes (RHS; MOBOT), and if flowering slows after the first flush, cut plants back hard and fertilize (MOBOT).

Are snapdragons toxic to cats?

No. The ASPCA lists them as non-toxic to cats, dogs and horses.

What is eating or damaging my snapdragon leaves?

Aphids are the main pest (RHS; MOBOT), and rust is the most significant disease (NC State). For aphids, see our aphid guide; for organic sprays, our neem oil guide.