Snapdragons are striking in both formal and informal garden beds. The tall flower spikes produce a profusion of blooms along their length in colors ranging from scarlet red to pale yellow. They are grown as annuals in most areas, as they do not tolerate frost at all. Snapdragons bloom from early summer until fall, adding an ongoing display of color in the garden. To keep them blooming profusely throughout the season they must be regularly deadheaded. Deadheading is the process of removing spent flowers before they go to seed, as once a plant begins producing seed it stops flowering.
Fill a bucket with 1 part bleach and 9 parts water. Rinse your pruning shears in this solution to sterilize them so you don't spread disease while deadheading the snapdragons. Rinse the shears in this solution each time you begin deadheading a new plant.
Examine the snapdragons for flower stalks that have petals beginning to whither and die. Cut off these stalks at the base where they emerge from the main plant. Compost or throw away the spent flower stalks.
Look for flower stalks that are already mostly bare, as these are starting to produce seeds. Look closely as you may mistake them for bare stems. Cut these stalks off at the base and dispose of them.
Deadhead the snapdragons at least once a week throughout the blooming period to prevent the plants from going to seed. When they are at the height of bloom in midsummer, you may need to deadhead twice a week.