How to Grow Antirrhinum Plants in your Garden

Gardener's HQ Guide to Growing Snapdragon and Dragon Flowers

The half hardy perennial Antirrhinum flowers from late spring through to the late autumn. Snapdragon is a sub-shrub.

It carries flowers that range in colour from vibrant red and orange through to pale pastel.

Brother Alfred Brousseau @ USDA-NRCS PLANTS Database. St. Mary's College of California.

Description of Antirrhinum

Antirrhinum ranges range in height from fifteen centimeters for dwarf species to as high as 65 cm for taller varieties; interestingly it is the taller varieties that are most sturdy with the dwarf varieties being quite floppy in nature.

Antirrhinum majus
Antirrhinum majus by Carl E. Lewis.

Antirrhinum Growing and Care Guide

  • Common Names: Snapdragon, Dragon flower.
  • Life Cycle: Half-hardy perennial. Often grown as a cold season annual.
  • Height: 6 to 48 inches (15—120 cm). Sub-shrub.
  • Native: Europe, Asia Minor, North America, North Africa.

  • Growing Region: Zones 7 to 10.
  • Flowers: Mid- spring through to the first frost of autumn.
  • Flower Details: Red, orange, pink, white, yellow, peach, purple. Bicolor varieties available. Colors can be vibrant or pastel. Flowers appear on spiked terminal racemes. Two lipped flowers.
  • Foliage: Herbaceous. Spiral leaves. Broad to Lance-shaped. Up to two and a half inches (7 cm) in length.

  • Sow Outside: Seeds: Surface under a cold frame. Late summer.
  • Sow Inside: Germination time: two to three weeks. Temperature: 55°F (13°C). Two months in advance of last frost. Transplant outdoors following the last frost or in autumn. Space at 6 to 16 inches (15—40 cm) depending upon species/cultivar size.

  • Requirements and care: Full sunlight for best results, or partial shade. Most soils (not heavy ones). Neutral soil pH and a richer soil should bring greater success. Feed before blooming. Water during prolonged dry spells. Susceptible to rust, molds, dusty mildew, root rot, and aphids. Pinch tips of young plants to encourage bushiness. Deadheading prolongs the blooming period. If plants do not produce a second bloom cut back hard and fertilize. Mulch if overwintering.
  • Family: Plantaginaceae.
  • Closely Related Species: Chelone, Digitalis, Veronica.

  • Miscellaneous: Gets its common names (Snapdragon, Dragonflower) because of the flowers resemblance to that of a dragon; pinching the flower causes the ‘Dragon’s’ mouth to snap. The same affect occurs when a bumblebee enters the flower, with the lips closing in on the bee to allow transfer of pollen. Antirrhinum plants have a complex taxonomy with botanists arguing which plants are true Antirrhinum and which belong to the Sairocarpus genus. The scientific name is derived from the Greek words for ‘like a nose’.
    Attracts butterflies and hummingbirds. Deer tolerant plant.

How to Grow Antirrhinum

It is best to sow Antirrhinum on the soil surface under cold frames in the late summer. Ideally Snapdragon should be sowed indoors eight or nine weeks before planting out.

If growing indoors, seeds should be allowed two to three weeks to germinate; they should then be grown at a temperature of around 13 degrees Celsius.

Antirrhinum should then be planted outdoors in the autumn at a spacing of fifteen centimeters for dwarf species and thirty centimeters for larger species.

They prosper in full sunlight, though they can also tolerate light shade if it is a necessity. The soil type is not that important but should not be too heavy; snapdragon prefers a richer soil of neutral pH.

Snapdragon by A. Gude.

Caring for Snapdragon and similar Species

Snapdragon is easy to look after; ideally they should be pinched back at the five or six leaf stage to facilitate a bushy growth habit.

Prior to flowering they require a couple of light feeds. It is important to deadhead plants following flowering to encourage further flowers.