When the leaves of a broadleaf evergreen are killed by the cold, don’t despair! It will often grow back from healthy lower tissue.
By Larry Hodgson
Question: I have had a rhododendron for a number of years and it did very well until this winter. But we had a really bad winter: the coldest in the last 30 years, apparently. Now the upper branches and flower buds are brown and I’m afraid it might be dead. Should I let it sit for a while to see if there is any life left in it? Or cut it back completely? Or dig it out?
Answer: Do let it sit for a while.
It’s never worthwhile panicking at the sight of winter damage to plants. This occurs quite often to rhododendrons and other broadleaf evergreens. Since they hold on to their leaves all winter, they readily lose water to excessive transpiration and that can indeed cause considerable leaf damage. Enough to leave the plant appearing in terrible shape by spring.
Typically, damaged flower buds turn brown and die. Upper leaves bend down, roll up nearly into tubes and turn brown. And instead of falling off, they continue to hang on to the plant.
But don’t prune right away thinking these branches are dead. It’s quite possible that the buds and brown leaves are hiding healthy replacement leaf buds that are still very much alive.
Instead, do a “scratch test” before doing any pruning. Scratch the bark below the damaged leaves with your thumbnail (or a penknife). You only need to remove a thin layer of bark, just enough to see the tissues underneath. If they’re green or yellow and a little moist, that means sap is still flowing through them. And soon as-yet unnoticed dormant buds will start to swell and then open into replacement leaves.
If the tissue underneath is brown or white and dry, on the other hand, the upper part of that branch is dead and you can remove it.
Ill.: JMcreation, depositphotos
Or just wait. If the plant is alive, it will eventually produce new leaves. Be patient, that can take a few weeks. And when new leaves start to appear, your shrub will regenerate little by little. At that point, it will be easy to tell which parts are alive and which are dead. Wherever nothing is growing, cut back to just above the part of the shrub where green growth is showing. That will ensure you’ve only removed the dead wood.
Other shrubs and trees too
The same scratch test applies to other shrubs and to trees showing damage due to frost or other causes. It even works with houseplants! It’s a pretty universal tool you can use whenever you want to know if a branch is dead or alive.
Remember, where there’s green, there’s hope!