October 2, 2014 | Posted in:Uncategorized
We’ve had many questions on this occurrence. So we wanted to get it out there what is going on.
I found this information at University of Illinois Extension website.
Autumn is the time of year when mature white pines annually drop older needles.
All trees and shrubs renew their foliage annually, producing new leaves in the spring of the year and shedding old leaves in the fall. The leaves of deciduous plants such as maples and oaks live for one growing season and then fall off, usually in a blaze of color.
Despite the name, evergreen foliage does not live forever. Actually evergreen foliage lives from one to several years, depending on the species. As new growth emerges in the spring, last year’s growth becomes shaded and is no longer the plant’s primary food. During fall, this inner or older foliage dies and falls away.
In some species like white pine and arborvitae, this fall browning takes place rather suddenly. The older needles turn a bright gold-yellow and remain attached for about 7 to 10 days depending on the weather. If we have strong autumn winds and heavy rains, these needles fall quickly. Sometimes, this natural occurrence is hardly noticed. But every few years it is very noticeable, and people become concerned.
This natural foliage drop may be distinguished from cases of severe foliage damage due to disease or stress by its uniform appearance over the whole tree and its common occurrence on neighboring trees of the same kind. It is also confined to the innermost or oldest needles. White pines bear needles in bundles of five and the needles remain together when they drop.