Horticulture : News
DATE: September 26, 2011
HARDIN COUNTY COOPERATIVE EXTENSION SERVICE
201 Peterson Drive
Elizabethtown, Kentucky 42701-9370
BY: Amy Aldenderfer
County Extension Agent for Horticulture
Not to Worry: Fall Pine Needle Drop Normal
Autumn is coming, and Kentucky hardwood trees are just beginning to put on their annual show of scarlet, orange and yellow. It's not a time of year when people pay much attention to pines, and many of those who do wind up worried.
The Extension office gets a lot of calls this time of year confusing normal fall needle drop with disease or insect attack. But a pine tree loses its leaves naturally, too, and it does it in the fall of the year. Pines needles just don't go through the colorful ceremony that hardwood leaves do.
The life of an individual bundle of pine needles is typically five to seven years. It's easy to determine whether pines are being attacked by insect or disease, or simply losing needles due to the time of year.
Normal needle fall affects only the innermost needles of the limbs, closest to the main stem of the tree. There's no need to worry unless you see foliage turning from green to brown on the exterior part of the limbs while it's still green on the interior.
Another tip-off is that the color change caused by fall needle drop is usually uniform, with affected needles on a tree turning the same color at the same time. In contrast, disease or insect attacks often produce several shades of brown on the same tree.
By early November the winds will blow the brown needles off and you won't see them anymore. The pines will be uniformly green again during the winter and ready for new growth in the spring.
Fall needle browning is normal for all Kentucky pine trees but is particularly obvious on white pines. Their limbs typically grow in whirls, rather like an artificial Christmas tree. Brown needles on the inner branches are easily visible because limb groups are set as much as three feet apart.
The interesting thing about the white pine is that it loses all its internal needles at once. It's not just spotty. A white pine puts on a whole flush of growth at one time and drops needles the same way, so they may lose needles for three or four feet on the inner limb closest to the trunk. You'll be driving along and see this nice green pine, but the whole inner section of the tree has turned brown. If it's on the outer part of the limb you've got problems, but there's nothing to worry about as long as the browning is close to the trunk. It looks dramatic, but it's normal.
Educational programs of the Kentucky Cooperative Extension Service serve all people regardless of race, color, age, sex, religion, disability, or national origin.
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