Snapdragons, with their dragon-like appearance and "mouth" that can open with a pinch of the sides, have been cross-bred and pollinated over decades to create a multitude of cultivars -- both with the traditional closed stamen and open for a trumpet-like look in different sizes and shades. Taller varieties such as Rocket, Liberty and Sonic grow to 3 feet in height and work well in cut gardens or in the back of border gardens for an early summer abundance of blooms in warmer growing zones, and all summer in the milder climates of northern growing zones. Tall varieties need some support, especially after rain, and do look best with something shorter planted in front of them to give texture and color to their tall stocks. A column of blooms will form on the stalk, opening from the bottom and moving upwards. Remove spent blooms for a longer bloom season. Check with your local full-service garden center in early spring for seeds or seedlings of cultivars best suited to your growing zone.
Medium-sized cultivars grow from 15 to 30 inches tall and are ideal as cut flowers or along border gardens. Popular varieties include Ribbon (in various colors), Kim and Solstice. Washington State University's Cooperative Extension office suggests pinching back medium-sized varieties after planting, to encourage new branch growth and create a fuller plant.
Dwarf varieties are ideal for containers and as low-growing border plants. Staying compact at 6 to 8 inches, dwarf varieties create a blanket effect where planted. Blooms spread vertically versus the horizontal blooms on tall cultivars. Some cultivars, such as the Floral Carpet series, boast being self-cleaning, meaning they do not need to be deadheaded to keep blooming through the growing season. Other popular dwarf varieties include Floral Showers, Montego, Tahiti and the trumpet-shaped Bells Mix series.