Antirrhinum majus: Snapdragon

This document is a part of a series originally written by Edward F. Gilman.

Introduction

Snapdragon is a popular landscape plant that is grown as an annual bedding plant (Figure 1). Snapdragons are notable for their corolla of large, colorful, zygomorphic (the top and bottom of the flower structure are symmetrical) flowers (Figure 2). These flowers are likened to a dragon’s snout, hence the common name. Snapdragon flowers may be red, orange, yellow, maroon, pink, white, purple, or multicolored. Plants with dark colored flowers have dark green or reddish stems, and those with white or pale flowers have pale green stems. This plant has an upright growth habit, and height ranges from 6 inches to 3 feet, depending on cultivar selection. The leaves of this plant are lanceolate and smooth and may be 3 to 6-inches in length (Figure 3).

This plant may be a short-lived perennial in USDA zones 7–11. In cooler planting zones, the plant will die back in the winter and need to be replanted the following year. Snapdragons make for a dramatic mass planting in the landscape, may be utilized as edging in the garden, are well-suited for container planting, and may be used as cut flowers in arrangements. In Florida, this species is best suited to being grown as a cool season annual and will flower until April or May. There are various cultivars with different flower colors and growth forms available, including tall and short cultivars.

General Information

Scientific name: Antirrhinum majus

Pronunciation: an-ter-RYE-num MAY-jus

Common name(s): snapdragon

Family: Plantaginaceae

Plant type: annual

USDA hardiness zones: all zones (Figure 4 and 5)

Planting month for zone 7: Apr; Sep

Planting month for zone 8: Jan; Feb; Mar; Oct; Nov; Dec

Planting month for zone 9: Jan; Feb; Oct; Nov; Dec

Planting month for zone 10 and 11: Jan; Feb; Nov; Dec

Origin: not native to North America

Uses: mass planting; container or above-ground planter; cut flowers; edging; attracts pollinators; attracts butterflies; attracts hummingbirds; deer resistant plant

Availability: generally available in many areas within its hardiness range

Description

Height: .5 to 3 feet; dependent upon cultivar selection

Spread: .5 to 3 feet; dependent upon cultivar selection

Plant habit: upright

Plant density: moderate

Growth rate: fast

Texture: medium

Foliage

Leaf arrangement: alternate

Leaf type: simple

Leaf margin: entire

Leaf shape: oblong; spatulate

Leaf venation: none, or difficult to see

Leaf type and persistence: not applicable

Leaf blade length: 2 to 3 inches

Leaf color: green

Fall color: not applicable

Fall characteristic: not applicable

Flower

Flower color: yellow; white; pink; orange; salmon; lavender; purple; multicolored

Flower characteristic: showy

Fruit

Fruit shape: round

Fruit length: less than 1 inch

Fruit cover: dry or hard

Fruit color: brown

Fruit characteristic: inconspicuous and not showy

Trunks and Branches

Trunk/bark/branches: not applicable

Current year stem/twig color: green

Current year stem/twig thickness: thick

Culture

Light requirement: plant grows in full sun; plant grows in partial shade

Soil tolerances: acidic; slightly alkaline; clay; sand; loam

Drought tolerance: low

Soil salt tolerances: unknown

Plant spacing: 6 to 12 inches

Other

Roots: not applicable

Winter interest: not applicable

Invasive potential: not known to be invasive

Pest resistance: long-term health usually not affected by pests

Use and Management

Snapdragons are short-lived perennials, generally utilized as cool-season annuals. They grow and bloom quickly, providing color in the landscape. Snapdragons may be planted in full sun to partial shade. They are adaptable to a range of soil conditions, given that the site is well-drained and slightly acidic. These plants exhibit low drought tolerance and may require additional irrigation during dry conditions. Set plants in the ground after the danger of frost has passed. Plant in the fall for winter color in USDA hardiness zones 9A to 11B. Plants sometimes survive and flower throughout the winter in zone 8B. Set the plants six to ten inches apart. Pinching plants back before flowering season encourages lateral growth and creates a fuller plant. This will delay flowering production until later in the season.

Bloom season is spring and fall in northern planting zones and fall and winter in southern planting zones. A second crop of flowers may be obtained from plants that have finished flowering. Cut them back to within 5 or 6 nodes of the ground when the first flowers fade. Fertilize when the second crop of flower buds become visible.

Propagation is by cuttings or seed. Seeds should be started 6 to 8 weeks before transplanting into the landscape.

Design Considerations

When using snapdragons in a landscape, their primary role is to add strong vertical lines and vibrant color to the garden. Effective placement depends on selecting the right height for the space: tall varieties create a striking backdrop at the rear of a border, while shorter types are well suited for edging, filling the front of beds, or adding height to containers. For the greatest visual impact, plant snapdragons in generous groups or blocks rather than as single specimens, creating a more cohesive and dramatic display of color. To add depth and contrast, pair their upright form with plants that have a softer, spreading habit to balance the snapdragons’ vertical shape and give the planting a full, finished look.

Pests and Diseases

Pest issues include aphids (sap-sucking insects which feed on terminal growth and undersides of leaves), greenhouse leaf tier (chews leaves and webs them together), mites (cause a bronze, stippled appearance). Disease issues include rust (brown pustules, yellow leaf tissue, small flowers), anthracnose (yellowish-green and gray spots along stem, stem girdling), gray mold (wilting flower spikes, stem breakage), stem rot (cottony growth on stems). Proper cultural practices encourage plant health.