As Thrive’s ISA Certified Arborist, Tina Graver is here to tell you how you can preserve the health of your trees the next time your yard’s under construction or you are building a new home.
What is tree protection and preservation?
Interchangeable terms, tree protection/ preservation is a service arborist’s offer for situations where trees can undergo damage or stress that, with the right plan, can be avoided or minimized.
“Trees are very prone to being damaged during construction,” Graver says. “Often, people don’t understand the extent that roots extend under the tree. The fact is that if you look at the height of a tree, the roots extend horizontally 1.5 times the height of the tree.”
She adds as you move further from the base of the tree, the roots become as fine as the grass roots—where even a seasoned arborist might have trouble telling the difference.
The critical root zone under the tree, also known as the drip zone, is the area containing the highest density of structural and absorption roots, and damage to roots in this area can be fatal to the tree. Tree protection is a series of services and physical barriers to protect the tree from damage to the roots, trunks and stems.
How does it work?
The process begins with a meeting between the certified arborist, the homeowner and other contractors on the job. The goal of the initial meeting is to understand what work is to be done and what trees will be impacted.
If possible, the arborist will try to direct the project, so there’s no need to interfere with the tree, except possible fencing to keep people, machines or equipment out of the critical root zone. If the only way to do the job is to impact the tree, a plan is made to mitigate the damage.
Common tools we use are:
Create a root pruning line: Here, we make clean cuts to the roots that will be impacted to prevent them from being torn and shattered. A clean cut will recover faster and the action of ripping the root from digging can result in a lot of root loss.
Prune the crown to give access to equipment: Again, we are trying to make surgical cuts and avoid trauma.
Make a road under the tree to distribute the weight of equipment: We can do this using mulch, crushed stone, traction mats and other products. The goal is to crush roots or disturb the soil.
Create a tree protection zone by erecting fencing to keep construction from spilling into areas under the tree. This includes stopping foot traffic and storage of equipment.
Install silt fencing along root pruned line to help avoid soil disturbance.
Soil remediation around tree, which includes mulching, relieving compaction and adding soil amendments and deep root fertilization.
Preventative treatments against pests and disease: Even a tree that undergoes tree protection can become severely stressed. Stressed trees are targets for pests and disease, so an arborist may recommend preventative treatments against boring insects or against diseases.
As a homeowner, sometimes you want to tackle these issues on your own. Graver advises against this.
“Call an arborist if you have a construction job and sensitive trees. I love the DIY attitude, but tree work can be complicated and dangerous. Always consult a professional,” Graver says.
And if that doesn’t convince you, Graver says know that a professional should always add “knowledge and peace of mind” to your project.