This residential property in Washington, DC features several larger trees at the rear, including a large diameter red maple (Acer rubrum) and ‘heritage’ sized Pin oak (Q. palustris). Another larger diameter red maple is found on the neighboring property. The homeowners did not want to kill their neighbor’s tree and wanted to keep the maple on their property. Because of the tree preservation laws within DC, the pin oak is a ‘protected’ tree.
In order to accomplish these objectives, the Tree Matrix review showed that by shifting the pool slightly to the east, that all of these trees would survive. Root pruning was restricted to the outline of the pool. The pool apron did not require root pruning because it was installed above grade to reduce the loss of roots. Root pruning was conducted during the dormant season. A small stair feature was added near the house that resulted in some root loss, so it is shown as a new boundary. It impacted a small portion of the root zone for tree 3, but not tree 2. Sediment control devices were installed above-grade, and mulch was added under the two trees.
TThe resulting survival scores suggest that this project will have minimal impact to all the impacted trees No other tree care treatments were suggested due to the high survival scores.
The trees are alive and doing well, one year after installation. The owners will undoubtedly have some leaves to clean from their pool going forward!
52" American Elm
Washington, D.C. Metro
Tree 1 is a large diameter Ulmus americana located in a residential lot. The owners wanted to develop the empty lot for a pool feature. It is assumed that the vast majority of roots for this tree elm were confined to this courtyard surrounded by a tall privacy wall. There was a small break in the wall near the sidewalk that allowed one large root to escape and grow toward the sidewalk. This is shown as the green cone of roots headed toward the road. This depiction is not representative of the actual rooting zone but is likely a good representation of the percentage of the total root zone comprised by this root.
The tree was weakened from previous root loss incurred a few years previous but was showing signs of recovery. A condition rating of ‘fair’ was given. In this condition, this tree was not a good preservation candidate to begin with. However, the extent of root loss from root pruning resulted in a survival score of 28% was assigned, assuming root pruning during the dormant season. A score this low should have precluded the development, even though the owners wanted to save the tree. Construction proceeded as shown and the tree died within one year.