Protect your Trees from Construction Damage

By Kim Gabel, Environmental Horticulture Agent

University of Florida / Monroe County Extension Service

Before construction work happens on your Keys property develop a tree protection plan to protect existing native and ornamental trees from damage.  Remember that construction equipment can injure a tree’s root system and trunk causing branch dieback and possibly a slow death.

Let’s review construction caused tree damage: soil compaction and trunk wounds.  Soil compaction is the single largest killer of a tree’s root system.  The reason being is that roots need to penetrate the soil structure to obtain oxygen, and absorb water and nutrients.  If the soil is compacted, it lacks good soil aeration, roots suffocate and tree health declines.  Therefore, stockpiled building materials, heavy machinery, and excessive foot traffic all damage soil structure.  Trunk wounding can cause major injury to the tree. Trees cannot replace injured tissue (heal) like animals, therefore injury permanently reduces the trees capacity to fight future stress caused by insects, disease or other factors.

Here are a series of steps to help lessen the damage caused by construction work.

Identify construction zone boundaries.  Get a set of site development plans that include the new buildings, utility locations, sidewalks, roads, parking areas, etc.  Identify where heavy equipment will be used, where soil will permanently be added and where fill and building materials will be temporarily stockpiled.

Perform a tree inventory and select trees for protection.  Record the location, size, and health of each tree.  Determine which trees are not in construction’s path that are structurally sound that need to be protected.

Protect these selected trees.  Install sturdy tree barricades surrounding the protected trees, preferably out to the tree’s dripline (edge of the branches).  The objective is to protect the root systems from soil compaction.  Make sure all construction workers know that nothing inside this area is to be raked, cut, stored, or otherwise disturbed.  A landscape protection contract signed by the builder and all contractors will help ensure compliance. Take several photographs of the site before construction begins to document the protection methods used and the condition of each individual tree.

Protect the trees for construction disturbance.  You'll boost your trees' chance for survival if you make sure they're as healthy as possible before construction begins.  Regularly water the trees if rainfall is not adequate. Fertilize them if soil tests or deficiency symptoms indicate they are nutrient stressed.  Prune branches that are low hanging, dead, diseased, or hazardous.

Monitor the construction process.  Visit the site regularly and inspect the trees.  Your presence alerts workers of your concern for the careful treatment of the trees.  Immediately inform the builder of any violations in the landscape protection contract and photograph the damage.  Insist that protective fences remain in place until all construction workers have left the site.

Make a final inspection of the site.  After construction has been completed, evaluate the condition of the remaining trees.  Look for indications of damage or stress.  It may take several years for severe problems to appear.  Careful monitoring and preventive treatment (e.g., watering) may help minimize damage.

Post construction tree maintenance.  Two important practices to help lessen construction shock are mulching and irrigation.  Mulching the tree protection zone with as much as you can, keep the mulch away from the tree trunk.  This will reduce water loss, control weeds and prevent runoff.  Also, irrigate the trees regularly during period of drought for several years to lessen water stress damage.

So by developing a plan to protect your trees from construction damage your trees will survive to provide you with shade, a wildlife habitat, and more.

Additional information is available from the University of Florida/IFAS/Monroe County Extension Office, 1100 Simonton Street, Suite 2-260, Key West, FL 33040; phone 305-292-4501; fax 305-292-4415; or e-mail monroe@ifas.ufl.edu. Our services are free and available to all without regard to race, color, sex, or national origin.