A wide range of snapdragon selections is available. The tall types are 2 to 3 feet tall, the intermediates are 1 to 2 feet tall, the bedding types are 6 to 15 inches tall, and the rock garden hybrids are about 6 inches tall. The flowers come in a wide range of colors from reds, orange, yellow, and maroon. Plants with dark-colored flowers have dark green or reddish stems and those with white or pale flowers have pale green stems.
Scientific name: Antirrhinum majus
Pronunciation: an-tur-RYE-num MAY-jus
Common name(s): snapdragon
Plant type: herbaceous; annual
USDA hardiness zones: all zones (Figure 3)
Planting months for zone 7: April; September
Planting months for zone 8: February; March; October; November; December
Planting months for zone 9: February; October; November; December
Planting months for zone 10 and 11: February; November; December
Origin: not native to North America
Invasive potential: not known to be invasive
Uses: mass planting; container or above-ground planter; cut flowers; edging
Availability: generally available in many areas within its hardiness range
Height: .5 to 3 feet
Spread: 1 to 2 feet
Plant habit: upright
Plant density: moderate
Growth rate: fast
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 4 inches
Leaf color: green
Fall color: not applicable
Fall characteristic: not applicable
Flower color: yellow; white; pink; orange; salmon; lavender; purple
Flower characteristic: showy
Fruit shape: no fruit
Fruit length: no fruit
Fruit cover: no fruit
Fruit color: not applicable
Fruit characteristic: inconspicuous and not showy
Trunk and Branches
Trunk/bark/branches: not applicable
Current year stem/twig color: green
Current year stem/twig thickness: thick
Light requirement: plant grows in part shade/part sun
Soil tolerances: acidic; slightly alkaline; clay; sand; loam
Soil salt tolerance: unknown
Plant spacing: 6 to 12 inches
Roots: not applicable
Winter interest: not applicable
Outstanding plant: not particularly outstanding
Pest resistance: long-term health usually not affected by pests
Use and Management
Snapdragons grow in any slightly acidic, garden soil, however, they do not grow well in unamended clay. The plants require full sun and moist soil. 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.
Snapdragons may be propagated by seeds, or by cuttings which root readily. The seed germinates in 10 to 14 days at 70-degrees F. Do not cover the seed with soil. Prechilled seeds germinate best. Seedlings with two to three sets of leaves are pinched, however, dwarf forms do not need pinching. Set plants in the ground after the danger of frost has passed. Plant in the fall for winter color in USDA hardiness zones 9 to 11. Plants sometimes survive and flower throughout the winter in zone 8b and south. Set the plants six to ten inches apart.
Dwarf cultivars include: 'Floral Carpet,' Floral Showers', 'Kolibri', 'Royal Carpet,' and 'Tahiti'. Intermediate cultivars include 'Princess', 'Liberty', 'Sonnet', 'Pixie', 'Sprite', and 'Cinderella'. Tall cultivars include 'Panorama', 'Burpee's Topper', 'Spring Giant', and 'Rocket'.
The warm-colored flowers of the snapdragon are a striking feature that can be used to bring color to a plant bed. Warm colors show best in full sun when paired with other plants with white flowers to make the red, orange, and maroon look more intense. Plants with dark green glossy leaves would also contrast well with the leaves of the snapdragon. Companion plants could include bold, large leaf textures in a tight clumping form or large-leaved small shrubs.
Pests and Diseases
Aphids feed on terminal growth and the underside of the leaves. The insects suck juices, and heavy infestations seriously weaken the plants. The greenhouse leaf tier chews irregular-shaped areas in leaves and webs the leaves together. Pesticides are seldom effective after the insect rolls the leaves. Mites cause a bronzed or stippled appearance on the foliage, especially in hot weather.
Rust causes brown pustules surrounded by yellowed tissue on the leaves. Plants may bloom prematurely, have small flowers, and die early. Use proper plant spacings and resistant varieties.
Anthracnose attacks the leaves and stems in late summer. On older stems the spots are sunken, oblong, yellowish-green to gray with a narrow brown border. On the leaves, the spots are yellowish-green turning dirty white with a narrow brown border. When the stem is girdled the plant dies. Destroy infected plants and use wider spacings.
Gray mold causes flower spikes to wilt and light brown areas form on the lower stem of the flower cluster. Infected plants break over below the flowers. The disease is worse in wet weather. Cut off infected flower stalks and keep beds free of debris.
Stem rot can be detected by the presence of cottony growth on stems of infected plants near the soil line. Infected plants die and should be destroyed.