Showing posts with label dripline. Show all posts
Showing posts with label dripline. Show all posts

Trees and Construction

Building your dream home on that wooded lot

By Amy McDowell

Wooded residential lots cost thousands more than treeless lots, but if those trees aren’t protected during construction, they can be severely damaged. Often the damage isn’t visible and the slow physiology of trees means they may live for four to seven years after construction crews have left the site, slowly spiraling into decline and finally death.


Soil compaction from heavy equipment and building materials is the most common damage. Ninety percent of a tree’s roots are within the top twelve inches of soil. Soil compaction may crush or tear the fine roots, but the loss of air space within the soil profile can be long lasting and even more devastating. Soil organisms can take decades to loosen compacted soils and return them to a healthy environment for tree roots.

The most important step to protecting the trees on your building lot is to ring them with a barrier that is not easily moved by construction crews. Metal stakes and bright orange snow fence works well. Place the barrier at least one foot from the base of the trunk for every inch of trunk diameter. For example, a tree with a two-foot diameter trunk must have a barrier at least 24 feet from the trunk.

Even after construction is complete, continue to guard the root zone. Don’t let a finish grader add or remove soil within the barrier zone. If you seed or sod the new lawn, use care not to drown the tree by irrigating too frequently. After the turf is established, water no more than once or twice a week.

A three-inch-deep mulch ring around the tree will protect the trunk from mower and string trimmer damage, and the wider the ring the better it is for the tree’s roots. Some arborists say a mulch ring that runs clear to the drip line of the branches would be a tree’s dream-come-true, although they realize that much mulch is unrealistic for most homeowners.

For large construction sites with complicated traffic patterns around trees, you might want to consult with an ISA certified arborist on how best to protect the trees. Information is available at www.isa-arbor.com or 800-ISA-TREE.