Q. I have a large pine tree in a natural area losing
limbs from the bottom up. It’s needles are browning and dropping. I don’t water
the tree much at all, but I have a water channel flowing 3 feet away on one
side of the tree. The channel is mostly filled with moving water and is about 1
foot wide.
A. It’s probably either water or light issue. Not enough
light because trees are planted too close together will also cause lower limbs
to die and drop. Sometimes light is not considered. Pine trees planted four to six feet apart are too
close together and lower limbs will die as they age.
 |
| An open canopy pine tree signaling that maybe the tree was either not receiving enough water OR it cannot get the applied water to the needles due to trunk damage. |
My guess
is that it’s water related; not enough. An easy way to find out is to put a
sprinkler on the end of a hose and give the tree one to two hours of water once
every three weeks to a month. I would use a non-oscillating sprinkler and
adjust it to about 8 feet wide. Use a four foot long piece of rebar to adjust
how many minutes to water.
 |
| Hose-end sprinkler. |
There
are two ways that I use to tell if a pine tree isn’t getting enough water; 1) I
look at the amount of new growth and 2) its canopy density. On well-watered, fertilized
smaller pine trees to about 20 feet tall, I like to see about 18 inches of new
growth and a solid canopy density. On older well-watered pine trees 40 to 60
feet tall the growth will be a lesser amount, perhaps 8 to 12 inches, but the
trees still have a dense canopy.
.JPG) |
| If growth is 2 to 4 inches when the pine tree is older then growth is not enough. Measure growth at the end of May after spring growth is finished. |
Pine
trees with drought problems usually grow 2 to 4 inches in length each year.
This small amount of growth translates into a very open canopy. Because pine
trees can have other problems as well such as borers and woodpeckers (sapsuckers),
I inspect the trunk for this kind of damage as well. A tree trunk with
extensive damage by borers or woodpeckers may also show signs of drought. Pine trees
with only a few inches of new growth each year and an open canopy usually
suggests drought.