Grown for its spires of colorful, two-lipped, tubular blooms, the common snapdragon (Antirrhinum majus) is a time-tested annual or short-lived perennial member of the figwort (Scrophulariaceae) family. Children are attracted to the bright blooms that resemble a dragon's snout and snap open when squeezed, and no worries there -- the plants are safe to include in gardens where children and pets play. Growing snapdragons in your garden is a fairly straightforward process so long as you keep a few important cultural facts in mind.
Snapdragons may be cultivated in U.S. Department of Agriculture plant hardiness zones 4 to 11, producing their best flowers in a location with full sunlight (though they will tolerate partial shade). Snapdragons are cool-weather lovers that are best grown during the winter in the warmer climates of USDA zones 9 to 11. They are far more tolerant of the frosts of spring than the temperatures peaks of summer. They can be included in a wildlife garden, as butterflies and hummingbirds are drawn to them while deer usually avoid grazing.
Snapdragons are suitable for most garden soils, so long as they are drain well. The flowers won't grow in clay soil unless it is amended with organic material for drainage. Newly planted snapdragons should be watered regularly, as much as once a day in sharply draining, sandy soils. Established plants should be watered once the top 1 inch of the soil is dry. To avoid leggy, sparse growth, pinch back stem tips. Remove spent flowers to extend the bloom period.
Rust is a serious snapdragon disease that causes symptoms such as brown pustules on leaves and premature, small, short-lived flowers. To help prevent rust, space snapdragons about 10 inches apart to allow air to circulate. If rust is present in a snapdragon bed, the Missouri Botanical Garden recommends growing the next batch of snapdragons in a different part of the garden. Snapdragons infected by anthracnose, a disease that causes spotting and girdling, or stem rot, which leads to cottony growth, should be dug up and destroyed.
Snapdragon seeds require light in order to germinate, so they must not be covered with soil. Instead, they should be pressed into the soil gently to hold them in place. Seeds take between 10 to 14 days to germinate at a temperature of 70 degrees Fahrenheit. Happy snapdragons often self-seed on their own if a few dead flowers are left on the plants to go to seed.