Now that November is here, any nice sunny day gives me the urge to be outside getting the gardens ready for winter. There is a lot of work that can be done now such as weeding, mulching, and cleaning up plant material that has died with the recent cold weather. There are also many tasks that we must hold off on until the weather has gotten a bit colder.
One of these tasks is wrapping evergreen shrubs, such as boxwoods, arborvitaes, yews, and hemlocks, with burlap. We wrap these evergreens to help prevent browning of the foliage. The main reason winter damage occurs in these plants is when the sun and wind cause excessive transpiration (foliage water loss) while the soil is frozen. The frozen soil prevents the plants from being able to replace the lost water. This results in desiccation and browning of the plant tissue.
Foliar damage often occurs on the south, southwest, and windward side of the plants. During a harsh winter, foliar damage can occur on all of the shrub. New transplants or plants with succulent, late season growth are particularly sensitive.
Protection can be created out of burlap and stakes. The barrier should be on the sides of the plant with the top remaining uncovered. The stakes can be pounded into the ground now, while the soil is not frozen. It is best to wait to wrap the plant until the ground is frozen so not to disrupt the shrub's internal winter preparation, known as hardening off.
If an evergreen has suffered winter injury, wait until mid-spring before pruning out injured foliage. Brown foliage is most likely dead and will not green up, but the buds, which are more cold hardy than foliage, will often grow and fill in areas where brown foliage was removed. If the buds have not survived, prune dead branches back to living tissue. Fertilize injured plants in early spring and water them well throughout the season. Provide appropriate protection the following winter.
Anne Lenox Barlow has had experience in the agricultural field as a horticulture educator with Cornell Cooperative Extension in Clinton County. She can be reached by e-mail at firstname.lastname@example.org.