Bright snapdragon flowers bloom profusely throughout cool weather in intensely saturated colors (almost every hue) and are real standouts in either the spring or fall garden. The flowers start blooming at the bottom of the stalk and work their way up, making for a long period of bloom. Although snapdragons tend to stop blooming in heat of mid-summer, if you keep them watered, they will perk up and carry your garden through the fall.
Snapdragons need adequate watering. When growing snapdragon, keep moist for the first few weeks. Once established, snapdragon will need approximately an inch of water per week in times of no rainfall. Water near the crown of the plant and avoid overhead watering to keep your snapdragon healthy. Once established, let the soil dry about an inch deep before watering.
Your snapdragons will bloom most profusely in full sun to partial shade in the spring. Once the temperature heats up, they may stop blooming altogether. Planting them in partial shade and keeping them well watered will help them make it through the summer and likely bloom again in fall. However, they are quick to get established and it can be just as easy to replace your snapdragon plants each season.
Apply fertilizer when the plants first start producing flowers. Use a standard, well-balanced all-purpose fertilizer, such as a 10-10-10 product, at a rate of three pounds for every 100 square feet of the flowerbed. Water well to minimize the risk of nitrogen burns and to help the fertilizer reach the roots.
Snapdragons like a neutral soil pH between 6.2 and 7.0. As short-lived plants, they are not heavy feeders, but adding organic matter will help keep them healthy and blooming.
When seedlings have developed about six true leaves, pinch off the top of the stem—this is primarily done with seedlings when they are three to four inches tall. Pinch the top off to encourage branching and bushiness.
Snapdragons prefer cooler temperatures. Snapdragons grow best when nighttime temperatures are in the low 40s and daytime temperatures in the low 70s Fahrenheit. Once established in the bed and hardened off, they can withstand sub-freezing temperatures. Make sure they stay well-watered during cold spells and add a layer of pine straw mulch, and they can last for quite some time. If you should get record low temperatures, cover snapdragons with pine straw for a few days until the chill has passed. Seedlings grown indoors do need to be hardened off for about 10 days to two weeks before planting in the garden.
