Friday, October 3, 2008

Landscape - Fall Needle Yellowing

This time of year, many inexperienced homeowners and landscapers get concerned with needle loss in some evergreens. Most often, this is the normal fall needle shed. The following is a short article on the subject.

Fall needle yellowing in white pines and other evergreens will start soon. If the oldest set of needles (those closest to the trunk) are yellowing and falling, that is normal for this time of year. This is not a disease, just the normal fall shed of the oldest needles. After a droughty summer and fall, needle loss will probably increase and is not a cause for alarm. If the newest growth is yellow, something else may be wrong and the cause should be investigated. Check for poor drainage, root damage or insect damage.

The fall coloring and loss of inner foliage is a natural occurrence of evergreen trees, including juniper (cedar) and arborvitae. The normal shredding of needles is most apparent on pines and spruce and results in numerous calls from alarmed tree owners. The critical factor is the age of the affected needle. Healthy pines retain their one- and two-year old needle while shredding their third. Healthy spruces retain their one- to six-year old needles while shredding their older ones.

Fall needle shed.

Information from Bob Mulrooney, Extension Plant Pathologist, UD and from the South Dakota State University Pest Alert

No comments: