If your evergreen turns brown, don’t panic
You say large sections of your evergreen tree recently started turning brown, and the tree looks like it’s dying?
Now is the time to practice patience. From late winter until early spring is typically the time of year when signs of evergreen winter burn appear. Before you remove a single branch, wait to see if any new growth emerges later this spring.
Recovery from winter burn sometimes appears to be miraculous. I still marvel at one of the prettiest arborvitaes in my yard. A few years back, it took such a hard hit in winter that I thought for sure it was dead. But the thing is, if the buds are still alive, new growth will emerge and gradually cover up the damage. When that happens, there may be little or no pruning required to make your tree look like new again.
The scientist in you might want to go out now to remove a couple of buds on an evergreen branch that looks dead. Open the buds to look for any green inside. If you see only brown inside the buds, you still might find green signs of life if you gently scrape off a little bark on a stem. But even if you don’t want to examine your tree up close and personal, you’ll know by the end of spring whether it will recover.
So what causes evergreen foliage to burn? Mostly weather-related conditions: Strong winds. Warm fall temperatures. Frozen soil, so plant roots can’t take up water to replace what is lost from the evergreen needles or scales. Wild temperature swings. Warm winter days followed by a polar plunge. An unusually severe winter. You’ll notice that the causes are mostly beyond a gardener’s control.
Nevertheless, there are a few things a gardener can do to help evergreens stay green. If late summer and autumn are dry, keep watering your evergreens regularly until the soil freezes. Maintain a 2- to 4-inch blanket of wood chips or other mulch around your evergreens. Don’t plant a new evergreen so late in the fall that its roots don’t have time to get established before the soil freezes. Don’t fertilize or prune evergreens in late summer or fall.
Most important of all, beware of deicing salts. Sprinkle calcined clay or sand instead on icy sidewalks and drives. If you’re clearing snow from an area where deicing salt has been applied, don’t pile it around your evergreens or where the runoff will reach them. If your trees are close to a busy street where salts are regularly applied, consider erecting a temporary burlap screen every winter to protect your trees. Such a barrier isn’t attractive but it could save your trees.
If the soil around your evergreens has already been exposed to salty runoff, thoroughly flush the soil with water a couple of times in early spring.
Jan Riggenbach will be speaking at the Siouxland Garden Show on Saturday, April 6, at the Delta Hotels Center in South Sioux City. Her presentation is titled “My Garden Mistakes” and runs from 10:45 to 11:45 a.m.