My Rhododendron Is Losing Leaves and Is Crispy

Winter Wind and Sun

• Rhododendrons planted in the full sun or on the south side of a home often suffer the most severe leaf scorch. The drying effects of the sun cause the rhododendron to lose water. Rhododendrons planted in an open area can also experience scorch from the drying effects of the winter wind. The margins of the leaves are the first region to lose moisture. The leaf develops a brown, crispy fringe.

Root System Injury

• A newly transplanted rhododendron is more susceptible to the drying effects of winter. Its root system is often unable to develop prior to the cold weather and may have been damaged during the transplant. The slightest bit of damage to the rhododendron's roots affects its ability to absorb water, especially during the dry winter. An established rhododendron's root system also can be damaged from excessive cultivation. Applying too much phosphate or lime may have the same effect.

Rodents and Ice

• In the summer, moles often burrow beneath the rhododendron shrub in search of grubs. After the moles move on, mice inhabit the tunnels during the winter and may chew on the rhododendron's roots. The rhododendron is weakened from injury to its root system. The damaged roots cannot adequately absorb water during the winter and the plant's leaves begin to show damage. Excessive ice buildup on the rhododendron's foliage during the winter also causes brown and yellow spots, even if the root system shows no damage. The sun shines through the ice crystals and burns the shrub's foliage.

Prevention

• Plant the rhododendron in a sheltered location where it will not receive the full force of the winter wind. Consider planting it in a shady spot on the north side of the house to protect it from the drying effects of the sun. Watch for moles during the summer and promptly fill in any holes the pests cause. Avoid overcultivation around the rhododendron's roots. Take care with the shrub's roots when transplanting. Applying mulch around the rhododendron helps keep the soil moist during the winter. Water the rhododendron in the winter months if the soil is not frozen.