Care of Rhododendrons in Winter
Caring for your rhododendrons through the cold season is easier if you understand how these plants are damaged to begin with. Cold injury in rhododendron is caused by too much water evaporating from the leaves at once, without anything to replace it. When cold, dry winds blow across leaf surfaces, they tend to take a lot of extra fluid with them. Unfortunately, in the winter, it’s not uncommon for this to happen when the ground is frozen solid, limiting how much water can be brought back into the plant. Without adequate water levels in their cells, the tips, and even entire leaves, of rhododendrons will wither and die.
Preventing Rhododendron Cold Damage
Rhododendrons attempt to protect themselves from winter dehydration by curling their leaves, allowing them to hang down. This mechanism is often effective, but there’s even more you can do to help protect your rhodies from winter damage. Since rhododendrons root much more shallowly than other plants, it’s extra important to keep a thick layer of mulch over this delicate system. 4 inches (10 cm.) of an organic mulch, like wood chips or pine needles, is often adequate protection from the cold. It’ll also slow water evaporation from the ground, helping your plant stay hydrated. Make sure to give your plants a long, deep drink on warmer days so they have a chance to recover from cold snaps. A windbreak made from burlap, lattice, or a snow fence can help slow those drying winds, but if your plant is already planted in a protected area, it should be safe enough from winter damage. A little bit of winter damage is okay; you’ll just want to cut out the damaged sections early in the spring so your rhododendron can get back into shape before the bleached leaves become an eyesore.
