How to Grow Snapdragon
Snapdragon Plants (Antirrhinum)
Whether you grow them as temporary annuals or tender perennials, snapdragon plants can be a great addition to flowerbeds, lending them color and height. Dwarf varieties of snapdragon may also serve as striking ground covers, reaching heights of a foot or less.
Depending upon the cultivars that you plant, you could have snapdragons in bloom practically year round—in spring, summer, fall and, in warm climates, early winter.
A luscious two-toned yellow, 'Lemon Sherbet' Antirrhinum is a good plant choice for a cutting garden or the back of a flowerbed.
Snapdragon plants bloom in just about every color imaginable, from fluttery white cultivars like 'Snowflake' to vivid beauties like 'Orange Wonder,' 'Lemon Sherbet,' 'Ruby' and A. nuttallianum or violet snapdragon.
Some snapdragon plants produce multi-color blooms. 'Oriental Lanterns' snapdragon, for instance, is a fall-blooming dwarf cultivar that produces striking red and yellow blossoms. 'Night and Day,' another bold bicolor snapdragon, produces tall stalks of crimson and white blossoms as early as spring and as late as fall, depending upon the climate.
'Twinny Bronze Shades' snapdragon is a tricolor beauty, producing orange, pink and rose blossoms on short, sturdy stalks in summer or fall, again depending upon the climate.
Many varieties of snapdragon bloom primarily in summer. No matter when they flower, however, cutting snapdragon plants back and feeding them with a slow release fertilizer will usually produce a second blooming—and even a third flowering. Often, summer-blooming snapdragon can survive the light frosts of autumn and may bloom into fall if protected from heavy frosts.
Snapdragons grow to varying heights, from one to three feet or more, depending upon the cultivar.
Dwarf cultivars that grow to only one foot or less are also available. Bicolor dwarf snapdragon cultivars like 'Oriental Lanterns' make a colorful ground cover. is another low-growing beauty, and 'Dwarf Magic' produces a lively carpet of red, orange, yellow and bronze snapdragon flowers. 'White Spanish' snapdragon
Annual or Perennial?
Although gardeners often treat snapdragons as annual flowers, they can also grow as "tender" perennials. In Zones 7-10, they will live year after year with a bit of care and protection.
Grow snapdragon plants in a full-sun location. Before planting, add organic matter. Snapdragon likes rich, moist soil with good drainage.
Snapdragon plants require little care, although they may need shade if the weather is extremely hot and staking if the plant stalks are very tall. Because they're prone to mildew, rust and aphids, it's also a good idea to keep them free of weeds, which attract insects and trap moisture.
Starting Snapdragon from Seed
To sow snapdragon seed, sprinkle it over moist growing medium. Then either lightly cover the seed with additional seed-starting mix or gently press the seed into the soil with your hand.
Next, to increase the likelihood of germination, stratify the seed. Stratification, the process of chilling moistened seed, encourages it to germinate.
If direct sowing snapdragon, do so in fall or early winter, and let nature take care of the stratification process for you.
Seed Buying Tips
Check the date. Although snapdragon seed is viable for up to 4 years, older seed will have lower rates of germination.
Avoid bulk buys. Discounted or bulk-buy seed is often old seed. It may also be impure, containing seed that you don't want, including weed seed.
Buy specific cultivars. By purchasing the specific snapdragon seed that you want, you'll be less likely to get nuisance plants that have traits you don't want, such as invasive proclivities and a tendency toward disease.
If starting snapdragon indoors, place the moist pots in the refrigerater. Some gardeners recommend a quick bout of cold (one to two days at most) to spur germination. Others recommend a one to two week period of stratification.
Without stratification, snapdragon seed is slow to germinate. Even with stratification, it may take the seed up to 2 weeks or more to sprout, even under perfect conditions: grow lights and temperatures at a steady 65 degrees F.
Once snapdragon seed does sprout, it tends to be leggy as it grows and may require careful staking. Snapdragon seedlings are also prone to damping off diseases caused by fungi. For this reason, it's best to start the seed in a soil-less mix, which is less likely to contain fungal spores.
About 9 weeks after germination, snapdragon seedlings should be large enough to transplant.
Collecting Your Own Snapdragon Seed
If collecting your own seed, cut the snapdragon stalks when about 70 percent of the seed capsules have dried. Place them on a screen to dry or upend them into a brown paper bag. After a week or two of drying, shake them to dislodge the seed.
Snapdragon plants self-pollinate, so you're likely to get seedlings that are very like their parent plants; however, thanks to the efforts of bees, which love snapdragon flowers, cross-pollination may occur.
If a cross does happen, the plants produced from collected seed are likely to have dark-colored flowers rather than light ones. Yellow and white blooms, for example, are a recessive trait, while red flowers are a dominant trait. Hairy stems are also a recessive trait, so crossed snapdragons are more likely to have smooth ones.
ABOUT THE AUTHOR
The Dirt Farmer has been an active gardener for over 30 years.
She first began gardening as a child alongside her grandfather on her parents' farm. Together, they would plant acres of vegetable gardens, setting tomato, eggplant and bell pepper plants; sowing row after row of beans and corn; and building up mounds of soil for white squash, pumpkin, cantaloupe and potatoes.
Today, The Dirt Farmer gardens at home, volunteers at community gardens and continues to learn about gardening through the MD Master Gardener program.