Evergreen damage is big concern

Q. My evergreen shrubs are brown/yellow in spots this spring. What is wrong?

— Jerry from Canfield, Dorothy from Canfield and many more

A. Winter freeze injury (aka winter kill or winter burn) has affected thousands of landscapes across the Mahoning Valley. The damage to evergreen shrubs seems to be the biggest concern so far from homeowners in the area.

Extension Educator Ashley Kulhanek made a list of the plants that horticulturalists from across Ohio noticed damage on thus far: magnolia, redbud, white pine, arborvitae, boxwood, ivy, Foster’s Holly, Japanese umbrella pine, rhododendron, forsythia, Canaan & Fraser Fir, yews, weeping cherry, viburnum, spruce and turf.

On evergreens, the damage occurs because evergreen plants continue to use water during the winter months. As the plant loses water, it replenishes water through the root system. If the ground is frozen, the roots cannot uptake water. This, combined with strong winter winds, can dry out several susceptible species quickly on cold nights. This winter was simply one of the worst in several years, affecting many plants.

The damage can look different depending on location of the shrub, the amount of or lack of mulch around the shrub, wind exposure and other factors. Some plants look most brown on the side facing prevailing winds. Be careful, though. Plants that look bad on the side facing a road, driveway or sidewalk may actually have salt damage. Also, last year’s high temperatures, high moisture levels and humidity, caused many shrub diseases you might not have noticed until this spring.

To prepare for next winter:

Mulch plants 2-3 inches in the fall to retain as much moisture as possible.

Where there’s exposure to prevailing winds, cover plants with burlap (see http://go.osu.edu/winterburn).

Keep evergreen plants watered properly until the ground freezes.

Meantime, hold off removing a plant or branch until you are sure it is dead. Eric Barrett is OSU Ext. educator for agriculture and natural resources in Mahoning County. Call the office hot line at 330-533-5538 from 9 a.m. to noon Mondays and Thursdays to submit your questions.