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Winter browning of evergreens
Brown
evergreen needles, needle tips and branch tips are a common sight during
the winter and early spring months in Colorado. These are all examples of
winter injury usually caused by the drying winds, lack of snow cover,
fluctuating temperatures, and low soil moisture that are typical of
Colorado's fall and winter seasons.
 Evergreen needles transpire or lose moisture during the winter months.
To keep functioning well, the plant must replace lost moisture through its
roots. But sometimes roots are unable to keep up with the moisture loss,
especially in windy conditions when water rapidly evaporates from the
needles. In some cases, there's plenty of soil moisture, but plants are
unable to absorb it, because the ground is frozen. In other cases, there
isn't enough soil moisture available to evergreens. As a result, the
needle tissue dries out, turning brown or red.
To reduce or prevent winter injury, water the root area of evergreens
during dry fall and winter months. When snowmelt and rainfall are
inadequate, apply water monthly during warm periods when the soil can
absorb it. Apply mulch over the root zone to help conserve soil moisture
and reduce loss from desiccation.
Although it's unattractive, winter injury symptoms are eventually
masked in the spring when new growth develops and old needles drop.
Affected plant parts don't usually need to be removed.
For "Fall & winter watering" refer to message number 1706.
For more information, see the following Colorado State Extension fact sheet(s).
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