Wind wreaks havoc on landscape trees
By Staff
Steve Strong / MSU Area Horticulturist
September 22, 2004
Everybody felt the effects of Ivan the Terrible this past week, as gale force-winds ripped through neighborhoods all across East Mississippi.
Home landscapes took a pounding, and trees that had been part of the community for generations came crashing down on houses, power lines and anything else in their path.
For residents cleaning up in the aftermath of the storm damage, now might be a good time to assess the overall quality of existing landscape trees, and decide on replacements for the ones destroyed by the hurricane. Several factors can cause certain tree species to be more wind resistant than others, including a strong root system, branching structure, leaf size and density of the canopy.
Folks along the Gulf Coast have to deal with severe storms on a regular basis, so wind resistant plants are a primary consideration for both residential and commercial landscapes. The Hurricane Center at Louisiana State University has determined that the native bald cypress (taxodium distichum and also t. acendens) is actually the most "hurricane-resistant" tree around.
Cypress trees have a number of wind tolerant characteristics, like fine textured leaves that drop in the fall, a growth habit with a well-balanced central leader, and a broad root system that penetrates deeply in most soils. Other species such as live oak, crape myrtle, winged elm, magnolia, tulip poplar, red oak, American holly, sweetgum, and Eastern red cedar also make the top 10 list.
Trees with a wide spreading branch pattern and a low center of gravity stand up better against tropical storms. Others may have a sparse canopy that allows wind to flow through the leaves and branches. Also, trees massed together in colonies tend to support each other more than solitary specimens planted out in the open.
Evaluating trees after a damaging storm can be challenging to the untrained eye, but the first thing to look for is broken or split branches that may still be attached to the main trunk. Severe splitting of the main trunk that removes more than1⁄3 of the bark circling the tree usually means eventual death of that tree, so get the chainsaw ready.
Large trees that have been partially or totally uprooted usually will not recover either, even when they are reset upright. This is due to the loss of feeder root tips that are torn away during uprooting and the rapid dessication (drying out) of the root system after exposure to air and sunlight. Replanting often leaves additional air pockets beneath the root ball that cause more drying problems later on.
The top three tree species chopped and hauled to the curbside this week appeared to be Bradford pear, water oak, and loblolly pine. Bradfords are notorious for their weak wood and inferior (narrow) branching pattern, and rarely last 20 years without ice or wind splitting them down the middle.
Water oaks have such a dense canopy combined with a weak root system that they remain a constant liability. If oaks are to be replanted, consider replacement with other species such as white, swamp chestnut, shumard or nutall oak. Pines are trees known for being self-limbing, and constantly drop lower branches as they grow, so if you plant them close to your house or driveway then prepare for headaches.
Trees are an invaluable part of the community and home landscape, and it important to choose species for their longevity and other attributes like storm tolerance. For more information on recommended choices for Mississippi landscapes, contact your county Extension Service office or visit the university Web site online at www.msucares.com.
