Q. We built our
dream house on a wooded lot, and took down as few trees as possible.
We love the shade they provide, and enjoy the close-up antics of
birds and squirrels. We have been in the house for a little over two
years, and are concerned about some of the trees. Some of them have
quite a few dead branches and do not seem to be doing very well.
What can we do to help them?
A. It would be
helpful to know the species of trees on your lot, since there are
problems such as the accidentally-introduced emerald ash borer
has been killing ash trees in the Pittsburgh area since before 2007.
However, it is likely that some of your trees are suffering from
construction damage; this is a common problem when construction
occurs near mature trees.
injures established trees in a number of ways:
• Heavy equipment
running over the roots of trees often damages the roots and
compacts the soil around them.
• Trenching for
utility lines, sidewalks and driveways, and digging out for the
foundation can remove or damage significant portions of the
trees’ root systems.
• Changing the
grade of the soil around the trees also takes its toll. Some
species of trees such as oaks are very sensitive to having
additional soil placed over their root systems. Even as little
as two inches of additional soil can cause life-threatening
problems for them.
mechanical damage to the trees can also be a problem, especially
if it involves a large portion of the trunk (trees can recover
from small injuries).
construction often radically alters the overall environment
including water drainage patterns, available light, new patterns
of pedestrian and vehicular traffic, and the use of deicing
salts where they were not used prior to construction.
often cannot adapt to such abrupt changes in their environment.
The stress also makes them more susceptible to disease and
may be surprised to learn that a tree’s root system can extend
out from the trunk one to three times the height of the tree.
The fine feeder roots, those responsible for absorbing water and
nutrients, are primarily found in the upper six to eighteen
inches of soil. Consequently, a tree’s root system can be
severely damaged even if equipment has not been working directly
under its branches.
a good idea to contract with a certified arborist before
construction begins. A certified arborist can help identify
which trees are worth keeping and which ones should be removed.
They also can work with the contractor to set up protection
zones around the trees you want to keep. These protection zones
are designed to keep heavy equipment away from the trees’ root
systems, prevent additional soil from being placed over their
root systems, and to protect trees from mechanical damage.
Is the Damage Done?
that the damage has been done, you would still be wise to hire a
certified arborist to determine if there is anything that can be
done to save your declining trees. If the trees are not too
far-gone, removing dead or dying branches, mulching, fertilizing
and cleaning up mechanical damage to the bark can prolong their
Many arborists also use air spades to remove excess soil
from over trees’ root systems without causing additional damage
to the roots as would happen with other types of digging
Arborists are certified through the International Society of
Tree replacements for Ash trees