Tree roots are the part of the tree below the ground that is not often thought about by property owners.

This has lead to a misconception
– The way the tree looks above ground, is the way the tree looks below ground
This is not true. The roots spread out at ground level, and tend not to go very deep. A lot of the critical roots are no more than 18 inches below grade. To picture what it looks like, visualize a wine glass.


The base of the tree extends out with the roots reaching way out past the trip line (the trip line is the shape of the outer part of the canopy) providing they have the space.

Property Construction and Root Pruning

When getting into property construction, and there will be an excavation that needs to takes place – the excavator will dig down with no consideration to the tree, causing a lot of damage very quickly to the roots of the tree. This is one thing that kills many trees in the urban environment, and the dangerous part is that the decline of the tree is not visually evident until a number of years later. The typical process for a death of a tree in a suburban area:

  1. Construction takes place to build property (including excavation)
  2. The house gets built
  3. The tree looks great and makes the property look pretty (short term)
  4. 4-5 years later branches start to die
  5. 6th year half tree is gone
  6. 10 years on and they’ll need to call in a Cohen and Master arborist. We’ll have to unfortunately tell them it was from their original house construction ten years prior.

From there it’s only a slow decline for the tree. Cohen and Master try to prevent that from happening via our root management protocols. This is necessary because once a large portion of the tree roots have been removed it can fatally impact the health of the tree.

If roots extend into the area of excavation, our arborist will set boundaries to make sure the tree is far enough away to handle a certain amount of its roots being removed. Anything greater than 20% of the roots being removed would be a concern to our Arborists as it will impact the health of the tree.

We at Cohen and Master also don’t want the roots to be ripped and hacked by an excavator or by pickaxe – what we do is dig a pit that exposes the roots by hand, using a whisk, or small hand tools, or by hydrovac (we blow out and vacuum all the soil with compressed air), so it removes all the soil and expose the roots. From there we make proper cuts on the line of excavation. The root can then compartmentalize and seal off there – allowing for new roots to sprout off from the cuts.

This really increases the chance of the tree surviving. It’s not something people think about a lot but it’s very important during construction.

If you are considering changes to your property that will likely impact the health of your tree please contact a Cohen and Master arborist for a free root pruning estimation.