Trees and Construction
Recommended Ornamental Plants for Southeast Texas
AgriLife Extension, part of the Texas A&M System, provides a website with recommendations for this area.
Think about TREES during CONSTRUCTION
BEFORE CONSTRUCTION: DESIGN FOR TREE SURVIVAL
Determine the Critical Root Zone (CRZ) for each tree, which is roughly a circle with a radius equal to the average dripline. Realize that most tree roots are in the top two feet of soil, and that feeding roots are in the top few inches Roots require non-compacted soil for both air and moisture.
Protect at least 75% of the CRZ. Fence the area to prevent traffic or storage of materials. If fencing is not possible, cover the CRZ with 6-8 inches of wood-chip mulch and 3/4-inch plywood or road boards to prevent soil compaction.
Route underground utilities to avoid the CRZ. If digging is unavoidable, bore under the roots or hand dig to avoid severing them.
Design paving away from CRZ. If this is not possible, use a porous material for driveways, such as crushed granite, pavestone, etc.
Save trees that are very close to buildings by using pier-and-beam construction techniques that allow air and moisture to reach the root zone.
DURING CONSTRUCTION: SAVE THE ROOTS, SAVE THE TREES
Set up tree protection guidelines and monitor compliance from initial grading of the lot to final landscaping and irrigation.
Maintain CRZ fencing. Mark access routes, storage areas and refuse sites.
Keep backhoes and other root destroying equipment away from roots, especially in the CRZ.
Avoid soil compaction. Park in the street, not under shade trees!
Use boring or tunneling methods when utilities are in the CRZ, since most roots are close to the surface.
Or dig hand trenches to avoid cutting roots.
Do not allow the disposal of paints, oils, unused mortar or other potentially toxic materials anyplace on the site.
If pruning is required, use correct National Arborist Association specifications. Do not expect pruning (or fertilizing) to compensate fully for destroyed roots.
Keep the CRZ well-watered during construction to avoid extra stress on trees. Saturate the top 4-6 inches of soil.
AFTER CONSTRUCTION REPAIR AND REMEDIATE
Remove contaminated soil, and aerate compacted soil. Make sure to maintain the same grade as before construction more than two additional inches of soil or sod can ultimately kill an otherwise healthy tree.
Monitor trees for up to five years, checking for insects or diseases that can strike a weakened tree.
Water trees during dry periods to help them recover from construction stress.
Fertilize annually with a slow-release non-burning complete fertilizer.
CHECK WITH AN EXPERT
There are so many species of trees and site possibilities that we can only offer general guidelines in this brochure. You’ll get the best advice about preserving trees from a qualified Urban Forester. Look for a person with a degree in urban Forestry or Horticulture and at least three years’ experience in urban tree preservation.