Seasonal Needle Loss

The Plant Disease Clinic has been receiving evergreen samplesshowing seasonal needle loss. (Many people panic at this time ofyear when they notice needles yellowing and falling from theirtrees.) Fear not, evergreens do not keep their needles forever. The older, inner needles eventually turn yellow or brown and fallfrom the tree.

White pines show the most noticeable needle drop. Usuallyonly one year's needles remain attached by November. Scots andAustrian pines generally retain their needles for three years. Needle drop is often not very noticeable on spruce and fir. On theother hand, arborvitae and some cedar needles turn brown ratherthan yellow with age and the change is quite noticeable.

Patterns of needle drop vary from year to year and from treeto tree. Adverse conditions in the summer and fall may lead tomore pronounced needle drop.

This article originally appeared in the September 16, 1994 issue, p. 139.

Category: 
Authors: 

Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Horticulture and Home Pest News, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on September 16, 1994. The information contained within may not be the most current and accurate depending on when it is accessed.