Important winter tree care tips
Winter weather, especially extremes in weather, can be hard on trees and shrubs. And while Nebraska is known for its often changing weather, broader extremes are becoming the norm.
We humans appreciate above average winter temperatures, but plants prefer an average and steady temperature. Warm, sunny winter days increase the risk of sunscald injury and winter drying. Lack of snow increases dessication injury while heavy, wet snows lead to broken branches and wildlife damage.
For young, thin-barked trees like fruit and maple trees, bark splitting and sun scald can be prevented by wrapping trunks with tree wrap or painting them with white latex (not oil-based) paint. It is most important to protect the south and southwest facing sides of young, tender barked trees.
Evergreens most risk of winter drying are newly planted evergreens but even established Arborvitae, Japanese Yew and some Junipers are susceptible. Evergreens planted in the last year or two and those planted near south facing walls of light colored homes are more at risk.
Winter dessication injury results in evergreens turning brown during spring. Adequate summer and fall moisture, without overwatering, is the best prevention. Our summer and fall rains this year were a big help, but if winter weather remains dry and warmer than average winter watering may be needed.
When soils are dry and not frozen, apply water slowly with a slow running hose or by punching holes near the bottom of a five gallon bucket. Place the bucket over tree roots and fill it with water, allowing the water to slowly trickle out of the small holes.
Watering at this time of year, or during warm winter periods, needs to be done early in the day for water to soak into the soil before nightfall. Water should not pool against a tree trunk to freeze over night as this can cause damage.
Placing a 4 inch layer of wood chip mulch over the roots of evergreens will help conserve soil moisture during the growing season and throughout winter. Mulch layers should not be too deep.
If deeper than 3 inches after the mulch settles, tree roots can grow up into the mulch and be killed by cold temperatures. Voles may also use mulch for protection and gnaw on tree trunks.
To protect broadleaf (i.e. rhododendrons) and needle evergreens at high risk of excessive drying by winter sun and wind, place canvas, burlap or polyethylene plastic screens to the south and west of sensitive plants. Evergreens near the south side of light colored homes are most at risk. Screens can also protect plants growing near streets from salt spray.
Shrubs like junipers and arborvitae can be protected from extensive snow loads by tying their stems upward and together with twine before heavy snowfall happens. On branches of evergreen trees, carefully brush away heavy snow loads with a broom to help prevent limb breakage.
Do not hit branches to try and knock snow or ice off as this may lead to branches breaking or developing cracks. Allow ice to melt naturally.
Kelly Feehan is a community environment educator for Nebraska Extension.