Yikes, My Pines Are
Dying! Otherwise known as Normal Fall Needle Drop
Gail Ruhl, Sr. Plant Disease Diagnostician, Dept.
of Botany & Plant Pathology, Purdue University
About this time every year we receive a number
of phone calls in the P&PDL
regarding yellowing and dropping of inner needles on pines. The
very striking and tend to alarm people. Rest assured, this phenomenon
natural one called Fall needle drop. It is normal for pines to
drop their oldest (inner) needles at this time of
year. Older arborvitae leaves turn a reddish brown. Natural
discoloration may be more noticeable on trees that have experienced
stress due to less than optimal growing conditions. Extended dry
during the summer months, as well as sites with poorly drained,
soils may accentuate root stress to pines. If the newest growth
needles) is still green and healthy in appearance, you can rest
this yellowing phenomenon is natural.
To improve the growing conditions around your trees
you may want to refer to
HO-140 , Fertilizing
Wood Plants (PDF 60K .
In addition, deep-core
aeration may help improve root growth by improving the soil structure
the percolation of water into the soil. To apply one inch of water
(the minimum needed during drought periods) you may need to run
a hose and
sprinkler or soaker at full capacity for 1.5 hours under the branch
(drip line area).
Click image to enlarge
Close up of normal fall coloration on white pine