Azaleas are popular ornamental shrubs known for their brilliant spring flower display. Whether they rebloom depends entirely on the variety. Traditional azaleas produce a single burst of flowers in the spring and then cease blooming for the year. Modern plant breeding has introduced hybrid cultivars specifically engineered to offer multiple cycles of flowers throughout the growing season, extending the color display into summer and fall. Understanding the differences between these types is the first step toward achieving a second or third round of color from your shrubs.
Identifying Reblooming Varieties
The fundamental difference between traditional and reblooming azaleas lies in the wood on which they set their flower buds. Traditional varieties are classified as “old wood” bloomers, meaning they form the buds for the following spring’s flowers on the previous season’s growth, generally in mid-to-late summer. If pruned too late in the season, these buds are mistakenly removed, resulting in no flowers the following spring. Modern hybrid azaleas, often marketed under brand names like Encore, Bloom-a-Thon, and Perfecto Mundo, have been bred to bloom on both old and new wood.
This genetic trait allows reblooming types to produce flowers on the new growth that appears after the first spring bloom. The ability to form flower buds on the current season’s growth is what enables the plant to cycle through multiple blooming periods. These reblooming cultivars typically maintain an evergreen presence and are generally more tolerant of sun exposure than their traditional counterparts.
The Timing and Triggers of the Second Bloom
Reblooming azaleas typically follow a pattern of three distinct bloom cycles throughout the year, although the intensity can vary. The first and most abundant cycle occurs in the spring, coinciding with the flowering of traditional azaleas. Following this initial flush, the shrub enters a period of vegetative growth, where it focuses on developing new shoots and foliage.
The second bloom generally begins in mid-summer, approximately two months after the spring flowers have faded. This summer cycle is often more sporadic than the spring display, but it is followed by a heavier, more concentrated bloom in the late summer and fall that can last until the first hard frost. Environmental factors play a significant role in triggering these secondary blooms, particularly consistent warmth and sufficient moisture during the summer months. The plant requires adequate hydration and energy to mature the newly formed buds, differentiating this process from the cold-dependent dormancy required by the spring bloom.
Specific Care for Consistent Reblooming
Achieving consistent reblooming requires cultural practices tailored to the variety’s growth habit. The timing of pruning is paramount; any necessary shaping or size reduction must be completed immediately after the initial spring bloom has finished. Pruning at this time encourages the rapid production of new growth, which is essential for setting the second round of flower buds. Pruning later in the summer or fall will remove the developing buds and eliminate the possibility of subsequent flowers.
Reblooming azaleas benefit from a specific fertilization regimen to fuel their extended flowering period. Use a slow-release fertilizer formulated for acid-loving plants, such as those labeled for azaleas and rhododendrons, after the spring bloom has concluded. This application provides the necessary nutrients to support new growth and bud formation without promoting excessive foliage, which can happen with high-nitrogen fertilizers. Consistent watering throughout the summer is also necessary, as insufficient moisture during the heat can cause the plant to drop or fail to form the developing buds for the fall show.