Since the issue with your rhododendron leaves seem to happen every spring, it sounds like you are dealing with winter injury. Rhododendrons lose water through their leaves in winter during times when it is warm and sunny. Since the ground is frozen, the roots are not able to take up enough water in the soil to make-up for what is lost through the leaves. There are a few ways to prevent winter injury, including adequate watering during the growing season.—about an inch a week—and especially in the fall to give your rhododendrons what they need for the winter. You also want to avoid fertilizing after mid-September because it may delay dormancy.
Periods of high winds can also cause winter injury and protection from winds can help prevent damage.
Hi Deb,
Since the issue with your rhododendron leaves seem to happen every spring, it sounds like you are dealing with winter injury. Rhododendrons lose water through their leaves in winter during times when it is warm and sunny. Since the ground is frozen, the roots are not able to take up enough water in the soil to make-up for what is lost through the leaves. There are a few ways to prevent winter injury, including adequate watering during the growing season.—about an inch a week—and especially in the fall to give your rhododendrons what they need for the winter. You also want to avoid fertilizing after mid-September because it may delay dormancy.
Periods of high winds can also cause winter injury and protection from winds can help prevent damage.