Saturday, May 21, 2011

Tree Problem 1: The Old Cherry Tree

Site: My backyard (NE Portland)


Biases:
+ There is something really cool about the shape of the branches and bark patterns on this tree. The dog loves to climb the tree to get a better view of the yard. It provides perch for birds and right of way for squirrels.
- The size, condition, and function of the tree are not a terribly good fit for the direction I am planning on taking the landscape in the back yard. It is in a spot that has pretty good sun exposure and would be nice for growing edible plants.


Tree Characteristics
Old cherry tree (Prunus sp.) an over-mature specimen tree with a single trunk branching low into two old branches with DBH 27" and 19". The larger has a vertical water sprout that has developed into a 8" diameter trunk where most of the active growth is taking place. Live crown ratio is around 60%. It has had some significant pruning and some broken branches.

Tree Health
New foliage looks healthy. Many branches are dead. Significant signs of decay.


Site Conditions
Residential site, northern aspect, shrub border with no regular irrigation. No signs of recent site disturbance, no paving, fill, or grade work in the dripline. Slope grade is at a transition from level to the North and 15 degrees to the south. Exposed to prevailing West winds.

Targets
Fence, landscape plants, garage.

Tree Defects
I suspect root rot (which was pointed out by an arborist who provided a quote for pruning or removal). There is a visible fruiting body on the trunk. No exposed roots, or root pruning.

A pocket knife inserted into a pruning wound went all the way in with little resistance. (See photo)
Just last night a 4" branch broke mid-branch.
Crown defects: Severe trunk decay. Conks on base of trunk. Severe dead wood on branches. Moderate previous failures.


Hazard Rating
Part most likely to fail: main branches. High failure potential on large parts with limited targets for a hazard rating of 3+3+1 = 7.

Hazard Abatement
Remove tree. Rationale: There is so much rot and decay that it appears the large branches are likely unsound. Pruning back to the vertical branch would result in a very strange form for the tree, and with the signs of root rot, perhaps even this would not be enough.

Other Recommendations
Evaluate leaving some dead wood for nesting habitat.

1 comment:

  1. Shasta will be very sad to see this tree go. I will too.

    ReplyDelete