Now that spring has sprung, it is the perfect time to get out into the landscape and take inventory of how the plants fared during the winter. We might have thought it was a ‘mild’ winter by Nebraska standards, but some of our trees thought otherwise. Winter desiccation is the major culprit for browning trees and the extent of damage to plants might not be fully realized until now.
Being observant of plant material can help determine if the plant was just dinged or if the damage was more severe. Brown or discolored foliage doesn’t always mean the plants are on their way out or beyond the point of no return. Winter desiccation can cause many evergreens to change colors. Evergreen trees and shrubs are constantly loosing moisture through their leaves during the winter. Winter desiccation happens when the root system isn’t able to absorb enough moisture to keep up with the amount lost by the leaves. It causes evergreens to have a brown or tan coloration at the ends of the needles. The damage usually occurs uniformly on the north or west sides of the tree or on the side that has a compromised root system. In most instances, supplemental water during the winter and spring can help to provide the much needed moisture and help to alleviate the symptoms.
The next task will be determining whether or not the branch or plant is still alive. There are a couple of options that you can use to test whether or not the twigs of a plant are alive. Take one of the plants’ brown branches near the end and try to bend the twig. If the twig is still pliable and the buds are big, healthy, and green looking, the branch is still alive and moving nutrients throughout the plant. If the twigs snap off readily and the buds appear brown and shriveled, the twig may be dead. Lastly, you can scrape away the outer layer of bark on the twig to determine whether or not the branch is alive. A live branch will have a green cambium layer, which moves nutrients, underneath the bark while a dead branch will have a brown layer. The last way to determine the fate of your plant is to wait until the leaves or new growth emerges. Once new growth or leaves have emerged, the branches without growth or those obviously dead can be pruned away.
Roses are one of the tricky shrubs. Some types of roses survive well in winter without any extra maintenance like the ‘Knock Out’ series and the rugosa rose. On the other hand, other types of roses, like the hybrid tea roses, require additional care. Be sure you know what kind of rose you have in order to provide the care it needs. Roses can also suffer from winter dieback in the canes, even the hardy ‘Knock Outs’. Wait to prune the rose bush until you know for sure what is dead and what is alive. Roses are normally pruned at the end of April or beginning of May once the buds have started to sprout and grow. Once the leaves begin to unfold, then you can carefully begin the removal process of the dead canes or the dead wood.
Some plants will do well in Nebraska only for little while. It takes a really trying year to find out which plants in our landscape are not extremely well-adapted to our growing conditions. Some of the plants that have fallen victim to Nebraska growing conditions this past winter were the Arborvitae and poorly placed yews, Taxus sp. If these evergreen shrubs didn’t received enough moisture during the winter season, they will turn brown or tan. Once these evergreens turn ever-brown, they might not fully recover.
Take inventory of the health of the plants in your landscape now. A little detective work early on can help spot problems in a timely manner so they can be fixed or new plants can be installed yet this spring.
Elizabeth Exstrom is the Horticulture Extension Educator with Nebraska Extension in Hall County. For more information contact Elizabeth at email@example.com, her blog at https://huskerhort.com/, or HuskerHort on Facebook and Twitter.