On Wed, 09 Feb 2005 10:24:39 -0500, Stephen Henning
wrote:

Nehmo Sergheyev wrote:
I have a cherry tree with a three inch (≈ mm) trunk, and I want to
landscape the ground upward around the trunk a couple of feet (
60 cm).- I just learned about Stem Griddling Roots (SGR)

Don't worry about Stem Girdling, worry about suffocation. Roots need to
be near air. That is why they grow along the surface rather than
straight down. Raising the soil level will suffocate the roots. Also,
bark on roots is designed to tolerate being under the soil. The bark on
the trunk is not and will either adapt or rot. Usually it rots.

Most people also forget that roots require oxygen. Raising the soil
level will suffocate roots. Often the effects of construction damage are
not immediately apparent. At one place the live oaks did not die from a
2-foot grade change until 10 years later.

If you built a retaining wall about 4 or 5 feet away from the trunk so
the fill didn't come up to the trunk, the trunk would be OK. Since the
tree is young, it might adapt to having the roots covered, especially if
you prune the top of the tree considerably to compensate for the
effective loss of roots. You many also have to install drainage tile if
the tree well would likely fill with water. This might not save the
tree, but it would give it a fighting chance.
I disagree with the suggestion to prune the top severely. Leaves make
energy, and you tree will need energy to recover from the stress of
root loss. Pruning out live tissue will reduce this energy production
while requiring energy expenditures to recover from the pruning.
Build the well and then, if branches die back over time, prune them
out later..

Keith Babberney
ISA Certified Arborist