How to Prune Mollis Azaleas

Mollis azaleas are the cold-hardy deciduous cousins of the more temperate evergreen azalea shrubs. Known botanically as Rhododendron x kosteranum, they flower in the late spring in warm hues of red, gold and apricot. Impressively, they are hardy in winter temperatures down to minus 25 F, but are also smaller than traditional azaleas, maxing out at 6 to 8 feet when mature. Pruning requirements are minimal and should be handled through deadheading during the bloom period and light shape grooming in summer, if warranted.

Things You'll Need

• Secateurs
• Loppers

Instructions

1. Deadhead the spent flowers on your mollis azalea as soon as they begin to fade and look shabby during the late spring. Consistent removal of old flowers spurs production of new ones. Pluck the dead blooms with your fingers or sever the short stem with secateurs, being careful to leave nearby buds intact.

2. Pinch back tender green shoots with your fingers in the spring and very early summer to force leggy, bare-centered shrubs to fill out with foliage and blooms. Do not do any pinching back after July to prevent loss of the following year's buds and blooms.

3. Lightly shape or perfect the outline of overgrown shrubs by trimming back the branch tips growing beyond desired boundaries. Do this kind of overall pruning, if needed, immediately after blooming has finished for the year. Make cuts on the bias with secateurs or loppers, roughly 1/4-inch above a healthy leaf.

Tips & Warnings

• Refrain from pruning later than midsummer to prevent loss of wood and bud sets that would bloom the following spring.

References

• University of Minnestoa Extension; Azaleas and Rhododendrons for Minnesota; Michael Zins; 2009
• Virginia Cooperative Extension; Growing Azaleas and Rhododendrons; Diane Relf, et al.; May 2009