UF/IFAS
Okeechobee
UF/IFAS
Okeechobee
458 Highway 98 North
Phone: (863) 763-6469
E- mail:
dfculbert@ifas.ufl.edu
Feature
Article - for release the week of
Dan
Culbert - Extension Horticulture Agent
Are your
Trees ready for the next one?
During the past two weeks I have
traveled over to
A few weeks ago we published an article about the effects of construction on trees. Let’s continue this idea with this week’s article on how to identify hazard trees around your Florida Yard. Prepare for the next storm by taking a critical look at your property now, noting the species of trees growing in your Florida Yard and their size and condition.
Ask yourself the following questions: If that branch should fall, will it drop on the roof or patio? Are the trees too close to the building? Is the tree so top heavy that wind will push it over like a sailboat, or are there holes in the canopy that will allow high winds to pass through? Are the major limbs strongly attached, or are there pockets of rot that have invaded the central core of the trunk? Do the limbs grow through power lines?
Decide if you have the tools and
skills needed to do the job, or hire a competent licensed professional.
Compare the cost of corrective tree pruning or removal to the costs and
inconveniences of repairing or replacing your home. Please
remember that any tree pruning activities need to be completed well before the
storm arrives – a pile of pruned branches can become missiles that can
multiply damage to your home and the rest of the structures in your
neighborhood.
According to
Blow-over -- The tree is physically pushed over by high winds.
Stem Failure -- Trees wounds don’t heal - they can only grow over old wounds and seal them off. Old injuries are weaker than normal solid wood, and can fail under high winds.
Jerking back and forth -- Abrupt wind gusts and calm periods can lead to stem breakage on trees with heavy crowns. When strong winds slow down, the tree snaps back, and if a massive crown moves too quickly, it may spring back too far in the opposite direction leading to stem damage and breakage.
Crown twist -- Tree crowns are never perfectly round. Many trees have lopsided crowns and heavy winds on one side of the crown produce twist (torque) on major branches and the trunk. Over time, the tree can adjust to handle twisting, but sudden hurricane winds can be too much. Stem twisting will be worse around old injuries leading to stem split or branch collapse.
Root Failure -- Roots may be confined by the buildings around them, can be diseased or damaged by construction, or just too small to support a large tree canopy. Windstorm stress can pull on the roots, snapping the roots and causing trees to lean or fall.
Branch Failure -- Branches are stuck into the side of the stem. Each year a small layer of stem wood called the branch collar gets bigger and helps to hold it on to the tree trunk. The branch collar turns downward and provides flexibility. If the branch attachment is V-shaped, it will be very weak; a U-shaped attachment is strong. High winds can “bounce” the stem up and down beyond the strength of the collar, breaking off the branch.
 |
left: Old wood rot in the trunk of this lifve oak caused stem failure Right: Jerking back & forth caused canopy branches to fail |
 |
 |
Left: crown twist takes out many pin trees in hurricanes. Right: root failure and wet soil caused this tree to blow over |
 |
While trees are not adapted to hurricane strength worst-case storms, healthy well maintained trees can ride out our average wind storms. Here are several ways to minimize the main types of storm damage:
Practice proper pruning techniques: remove undesirable branches before they become larger than one inch in diameter, and don’t cut into the branch collar.
Prune forked branches and those that arise opposite each other to eliminate codominant branches early in the life of the tree. Removing one side now will prevent losing the whole tree later if it splits in a storm.
Keep trees as healthy as possible with timely watering and proper fertilization. However, don’t overfertilize or overwater the tree which top-heavy growth and makes the tree more susceptible to storm damage.
Eliminate lopsided crowns. Prune branches to produce a reasonably symmetrical crown. If more than 70 percent of the crown is on one side of a mature tree, consider tree removal and replacement.
Remove or treat pest problems, like branch cankers, to minimize potential damage. Do not over-treat tree hollows. Do not remove decayed wood from hollows as it can lead to further internal damage. Covering rather than filling the opening will allow the tree to grow over the hole, prevent animals from expanding it, and reduce the amount of water from running in.
Keep the tree growing upright and prune away branches that compete with the main stem. Eliminate branches with tight or narrow V-shaped crotches.
I have placed some photos
on the internet due to hurricane Charley. If
you need additional information on preparing your landscape for windstorms, take
a look at the references on our internet site, http://okeechobee.ifas.ufl.edu
or email us at okeechobee@ifas.ufl.edu.
Area residents can call us at 863-763-6469 or stop by our office at 458
Hwy 98 North in Okeechobee. You can visit with our
-30-
References
Gilman, Ed. Storm
Preparation and dealing with the aftermath.
ibid. Restoration Pruning. Gainesville: UF/IFAS Department of Environmental Horticulture. August 2004. http://hort.ifas.ufl.edu/woody/pruning/restore.htm
ibid. Treating storm impacted trees. Gainesville: UF/IFAS Department of Environmental Horticulture. August 2004 http://hort.ifas.ufl.edu/woody/maturetreecare/stormdamage.htm
National
Arbor Day Foundation. Reducing Tree Damage in Future Storms. (In
cooperation with the USDA Forest Service and the International Society of
Arboriculture.) http://www.arborday.org/media/stormsectionf.cfm