Although the snapdragon (Antirrhinum majus), a short-lived perennial usually grown as an annual, can flower in U.S. Department of Agriculture plant hardiness zones 4 to 11, its blooming cycle depends on the region. It is almost always snapdragon season somewhere; however, the charming, old-fashioned flower favorite refuses to bloom when temperatures consistently top 80 degrees Fahrenheit. Therefore, plant snapdragons in the spring for summer and fall flowering in areas with mild summers, and set them out in the fall for USDA zones 9 through 11 for winter and spring blooms.
Choosing Which to Grow
Snapdragons come in an array of colors, sizes and flower shapes, so when selecting, consider their purpose in the landscape Tall varieties such as "Rocket" and "Topper" that grow to 4 feet and need staking, shine when planted against walls or along walkways. Consider intermediate types in the 1- to 2-foot range, such as "Princess White with Purple Eye," for rock gardens. Dwarf varieties, such as "Magic Carpet" and "Little Gem," only reach 6 to 8 inches and excel in containers. Trailing cultivars tumbling over the sides of hanging baskets add color to patios. Classic snapdragon flowers have two puffed petals, but newer varieties surprise with double flowers, bell-shaped blooms and fringed or ruffled azalea-like blossoms. Snapdragons bloom in white and shades and tints of red, yellow, orange, violet and purple, as well as color combinations.
Enjoying Winter Blooms
Snapdragons are cool-season flowers, meaning they blossom best spring through fall, or fall through winter, depending on the climate. They splash the garden with color in winter when grown in mild-winter areas such as Oregon, Florida and coastal California. Their lively blossoms bring cheer during an otherwise drab season. If growing for winter blooms, set snapdragons out in early autumn, and if the bud temperatures fall below 50 degrees Fahrenheit, you can expect blooms that continue until late spring. Under favorable growing conditions, snapdragons will self-sow in southern gardens to return the next year, but for best results plant annually.
Enhancing Your Landscape
Offering an abundance of assets, snapdragons add casual splashes of color to informal gardens. Their long-lasting flowers can become so profuse that they hide the leaves during peak blooming periods. Tall varieties, particularly, form the centerpiece in attractive flower arrangements. Cutting gardens often include them for this purpose . Some varieties release a pleasant fragrance. Butterflies seek snapdragon flowers; deer do not. Native to the Mediterranean region, snapdragons are easy to grow but not invasive.
Promoting Longer Blooming
Pinch the tips of seedlings when they reach about 4 inches tall to produce extra flower spikes. Cutting flowers for indoor vases as soon as they appear will encourage snapdragon plants to create more blooms later in the season. Remove spent flowers for longer bloom. Maintain snapdragons' general health by planting them in fertile, well-drained soil in a sunny site. Water from underneath by drip, bubbler or flood irrigation to discourage the development of rust, a disease to which they are prone.
- Floridata: Antirrhinum Majus
- University of California Cooperative Extension: Snapdragons
- Cornell University Extension: Snapdragon
- The New Sunset Western Garden Book; Kathleen Norris Brenzel, Editor
- Photo Credit Hemera Technologies/AbleStock.com/Getty Images