Snapdragon care and cool-season planting

Snapdragons (*Antirrhinum majus*) are cool-season annuals that most gardeners treat as a spring plant -- transplanted after last frost and expected to bloom through summer. This misunderstands the plant. Snapdragons bloom best when temperatures are between 40–70°F. In most of the eastern US, this.

Snapdragons (Antirrhinum majus) are cool-season annuals that most gardeners treat as a spring plant — transplanted after last frost and expected to bloom through summer. This misunderstands the plant. Snapdragons bloom best when temperatures are between 40–70°F. In most of the eastern US, this means spring and fall, with a dormancy or significant decline during the hottest weeks of summer.

Understanding this cycle — and planting accordingly — is the key to getting consistently good performance from snapdragons.

Zones and temperature requirements

Per Missouri Botanical Garden, Antirrhinum majus is a tender perennial in zones 9–11 (where it survives mild winters) and a cool-season annual in zones 3–8. It performs best when daytime temperatures are 60–70°F and nighttime temperatures are 40–50°F.

Per NC State Extension, snapdragons are more cold-tolerant than most annuals. Hardened transplants tolerate light frost (to 26°F). This cold tolerance enables setting them out 2–4 weeks before the last frost date, extending the spring bloom season significantly.