What can be done to help sick trees?

Question: I just bought a new house in a subdivision and noticed that large trees near my home and other existing homes were sick looking this past summer. What do you think is wrong and can anything be done at my new home to help the trees?

Answer: Construction can be devastating to trees if nothing was done to protect them prior to the grading work for home construction. The damage to the root systems often results in tree loss by a slow and “painful” death. Ideally a trained arborist (tree expert) should have been consulted during the planning stages of construction. Trees can be preserved if the appropriate measures are taken soon enough. Unfortunately, it is usually when the first signs of decline appear that help is sought and by then the patient is very sick and the prognosis is not good.

If you decide to consult with a professional arborist make sure they are a certified arborist with the International Society of Arboriculture. You can look this up on the internet at their web site: www.treesaregood.com

There are some things you can do if you start soon after the damage occurs. First, the most important tree maintenance procedure following construction damage is to maintain an adequate, but not excessive, supply of water to the root zone. A good soaking about once every couple weeks is much better than frequent, shallow watering. This one thing will likely do more to help trees recover from construction stress than anything else you could do. The long range winter weather forecast is calling for a drier than average winter, so you may want to water even during the winter if the forecast turns out to be correct.

Second, mulching is the simplest and least expensive thing you can do for your trees. Applying a 2- to 3-inch layer of organic mulch such as wood chips, shredded bark, or pine needles over the root system does several things. It helps condition the soil allowing for better water infiltration, moderates soil temperatures, holds moisture, and reduces competition from weeds and grass. The mulch should extend as far out from the tree as practical for the landscape site. Do not apply the mulch any deeper than 4 inches, and do not pile it against the trunk.

Last, do not plant grass (or other plants if you can avoid it) under the trees. Anything you can do to reduce competition for water and nutrients is good. Remember, it may take several years of pampering for trees to overcome damage done during construction.

For those who want to learn more about preserving trees during construction mark your calendars for January 11, 2011. The Alabama Cooperative Extension System, CAWACO RC&D and The Regional Planning Commission of Greater Birmingham are sponsoring a “Tree and Development” workshop at the Birmingham Botanical Gardens. Visit this web site for more details: www.aces.edu/trees.

For more about this topic please contact Tony Glover, Regional Extension Agent-Home Horticulture, Home Gardens and Home Pest Management at the St. Clair County Extension Office at (205) 338-9416 or email gloveta@aces.edu.