My Rhododendron Leaves Are Curling in the Winter

Location

• Unless you are planting the rhododendron in a container that can be moved when cold weather approaches, it is important that you plant it in a location that protects the shrub from harsh environments. Select a planting location that shields the plant from harsh winds and direct sunlight. This shade lover thrives best when planted near trees and buildings as these structures provide protection from the harsh elements while filtering the sunlight to the shrubs.

Soil

• The rhododendron requires loamy, well-drained soils for best growth. The rhododendron’s shallow root system also demands acidic soils with pH levels between 4.5 and 6.0. Always test the soil’s pH levels before planting the rhododendron shrub and adjust the pH levels, if necessary, before planting it. The rhododendron shrub is a light feeder and only requires fertilization during early spring. Avoid feeding this shrub throughout the growing season, as the tender roots are easily burned by fertilizers and can make the shrub susceptible to winter injury.

Protection

• Mulching the rhododendron shrub’s planting area helps protect the shrub from winter injury and leaf curl. Apply the mulch around the shrub’s planting area in the fall. Keep the mulch about an inch away from the stems and base of the shrub to allow the wood time to harden before the winter months. Add additional mulch around the shrub and near its base just before the winter’s first hard freeze. Feel free to wrap the rhododendron shrub loosely with burlap or cover the shrub with a snow fence to provide additional protection.

Considerations

• There is not much that can be done to reverse the rhododendron’s leaf curl once the winter months arrive. Along with leaf curl, the rhododendron shrub can experience splitting bark, wilt and deadened blooms as a result of exposure to the winter elements. Remove any protection around the shrub in the late winter to early spring. Prune away any dead or damaged stems and foliage. Take a soil sample to determine the planting location’s pH levels. Make any required adjustments to the soil, fertilize lightly and line the planting area with fresh mulch.