Recent weather events have taken a toll on some of our older established evergreen trees. Most recently, our heavy wet snow that collected on the evergreen boughs added many pounds of weight and broke out branches throughout the canopy. The wind played a big part of that damage, creating more pressure on the limbs. Most damaged were evergreens with long limbs like white pine and Norway spruce, the very ones that show less damage from other needled evergreen problems. Mother Nature decided to even the score I guess. If you can, make an appropriate, clean cut to allow the wounds to heal properly or consider using an arborist to do that.
In most winters, gardeners would expect to see some degree of needle desiccation going on from drying winter winds coupled with routine winter sun exposure. Recently transplanted needled evergreens with a limited root system will have more needle damage than established ones. The severity of damage is a function of how much internal moisture was lost over the winter. This varies from just yellow or brown needles to complete loss of those needles, perhaps even bud, and twig death.
On younger seedlings and one- or two-year-old transplants, entire trees can have symptoms that indicate a complete loss. All the needles top to bottom take on a dull green color. They can be brittle, letting you know all the internal moisture has been lost too. It will be a few weeks down the road before you will know the extent of all the damage was. Older trees can have cracked and stressed limbs that show up later as the summer temperatures and drying weather arrive.
For those needled evergreens with one or more of the needle blight and needle cast diseases, consider making fungicide treatments to stop the cycle of older needles infecting the new needles. This is a good start for plant recovery. Often the label will state the first spray goes on when the new needles are half grown / expanded and another when the needles are full-grown or nearly so. If your evergreen trees are healthy, there should be at least two or maybe three years' worth of good green needles on every branch. Other parts of recovery include watering in the summer months, long before any declared drought. Completely moisten the soil from a few feet from the trunk and beyond the drip line by several feet. A fun fact is it takes 680 gallons of water to apply 1 inch of water over 1000 square feet! Additionally, annually fertilizing, using a quality tree and shrub fertilizer product, helps the evergreens return to a better state of health, making the plants more resistant to disease and the ability to recover better.
About the author: Richard Hentschel’s expertise extends across several subject areas with specialties in lawn care, fruit tree production, woody ornamentals, and home and community gardening. During his 45-year career in horticulture and agriculture, Hentschel became a well-known and respected expert for commercial and homeowner audiences, industry organizations, and media. He retired from University of Illinois Extension in April 2022 with nearly 30 years of service as a Horticulture Specialist and Educator in northern Illinois.