Snapdragons have noses and little mouths that open when the bloom is pinched on either side. These curious, prolific bloomers are a garden favorite for colorful blooms, spiky height and continuous blooming capability even in cool temperatures. Caring for these "mini dragons" is simple with routine maintenance.
Fertilize snapdragons by testing the prospective planting site for pH prior to sowing seeds or planting starts. Local University Extension offices can perform a soil test for nitrogen, phosphorus, and potassium levels and suggest amendments to keep your flowers blooming beautifully. In addition, prepare the soil yearly with organic material, tilling it to a depth of 3 to 5 inches. In areas where the snapdragons over winter, wait to fertilize the soil until after the blooms are spent if you plant to re-sow seeds or plant starts that late summer or early fall.
Plant starts in well-drained soil in a location that will not become soggy with heavy rain or during irrigation. Although snapdragons love the sun, very hot temperatures will wilt and scorch them. Extended spring and fall blooms are not uncommon, but mid summer heat prevents snapdragons from surviving the complete growing season from start to finish. In some areas of the country that maintain mild warm weather year round, snapdragons can behave as a winter annual, dropping fall seeds, overwintering and sprouting to produce a crop of spring blooms.
Sow seeds in a sunny area, in well-drained soil after danger of frost is past. Scatter seeds across the top of the soil, leaving them uncovered. Water and protect the seeds from disturbance until germination--10 to 14 days in warm weather. Thin strong seedlings to 12 inches apart. If you are starting seeds indoors, plant the seedlings out after the frost date. Harden the seedlings off by keeping them outside a few hours more each day until they are outside all day and all night, then plant them in the ground.
Pinch off spent blooms and remove spikes that have stopped flowering to encourage new growth and more flowers. Cut stalks back to several nodes or bud spots just above soil level to encourage a second crop of flowering stalks to emerge later in the season.
Snapdragon varieties range in height from 6 inches to 3 feet, so knowing your species is important for routine care. Floral Carpet, Royal Carpet and Tahiti series are all dwarf plants, which do not require staking. Intermediate snapdragons grow 1 to 2 feet tall, including the Ribbon series and Princess White or Purple Eye, and may require staking. Amongst the tallest, 3-feet spiked varieties, the Rocket, Liberty and Sonnet series need support and staking in order to stand erect. Stake snapdragons using simple wooden dowels or canes, firmly stuck in the ground and attached loosely to the stalks with garden twine.