Winter Damage on a Rhododendron: Although the leaves may be brown and curled, this doesn’t necessarily mean the plant is dead. In fact in most cases the plant will rebound easily with a little TLC.
After a long, cold, snowy winter like we just had, we often see damage to our shrubs and trees often called “winter kill” or “winter damage.” The most common damage is brown or dead-looking azaleas, rhododendrons, holly and other broadleaf evergreens. Most people assume cold temperatures are to blame, but it’s actually caused by dehydration. In winter, cold dry winds and bright sunshine suck moisture from the foliage of broadleaf evergreens, much like chapped lips after a day of skiing. Plus, because the ground is usually frozen and the plant is dormant, plants can't move water through their roots back to theire leaves. The result is dehydration, browning the tips of leaves or even entire branches. The more exposed to wind and sun, the greater the damage; particularly heartbreaking when it happens to shrubs you’ve loved for 20 years or more. Yes, sometimes the plant is dead and will need to be replaced, but often winter damage only make shrubs appear dead.
How do I know if it can be saved?
Look carefully and you’ll see that the leaves may be brown and brittle but the branch may have good life. Try gently scratching the bark with a fingernail, if underneath it’s greenish and pliable it’s probably still alive. If under the bark is brown and brittle the branch is probably dead – but not necessarily the whole plant. Continue the exploration down the branches and you will probably see some life along the way. Usually I tell people to leave winter damaged shrubs alone until late May. By then you can see the new growth starting, making it easier to see and prune the brittle dead wood. In any case, don’t give up on them to soon – in early spring, winter damage often looks a lot worse than it really is! All you need is a little patience and a good organic fertilizer.
The Scratch Test: Try gently scratching the bark with a fingernail, if underneath it’s greenish and pliable it’s probably still alive. If under the bark is brown and brittle the branch is probably dead – but not necessarily the whole plant.
Holly-tone by Espoma: Use it on all broadleaf evergreens like Rhododendrons, Azaleas, Holly, Boxwood and Andromeda.
Help the recovery with a good organic fertilizer.
I can remember I had a Holly and an Azalea that turned completely brown from winter damage. Then after feeding with Espoma Holly-tone fertilizer and some warmer weather from Mother Nature both plants completely re-foliated and grew back to where they were the previous fall. This saved me the time and effort of replanting the shrub. The earlier in spring you take action the better because it will allow more time for the bare branches to re-bud and start to fill in. There are other products to choose from, but Holly-tone is easy to use and it’s worked well for me. If there is mulch around the base, just push it away to expose the soil. Scratch the soil surface a little to allow for good soil contact and spread Holly-tone around the drip line of the shrub (the area under all branches). Just follow instructions on bag for proper quantity. Then just replace the mulch, water and wait for the magic healing to begin. You may need to go back and do some tip pruning later to cut out some dead wood but it’s far better than throwing out a live plant.
There are several products that help prevent winter kill. They’re called “anti-desiccants,” a kind of a sunscreen for plants. Spraying an anti-desiccant places a harmless transparent wax coating over the broadleaves. The effect is to reduce the dehydration caused by wind and sun. Typically it’s applied after the first really cold nigh in late November or December. At Mahoney’s we recommend Wilt Stop by Bonide, but there are other good products to choose from.