Wednesday, July 17, 2013

Assessing Wind Damage to Trees

On Friday severe wind and storms came racing through parts of metro-Atlanta, damaging property, power lines and landscape trees and plants. Meterologists called the storm a "microburst" meaning that strong winds hit the ground and traveled straight, unlike the spinning winds of a tornado. 

If this happened to a property you manage, give CrabappleLandscapExperts a call and let us explain the steps that our professional landscape maintenance service performs after such a wind event.

The LandscapExperts Make Observations
We approach damaged trees with caution, particularly if there are large dangling branches or power lines caught in the trees. Call the LandscapExperts if in doubt (770-740-9739)

Crabapple Assesses the Damage

Uprooted multi-trunked tree
Q Was the tree uprooted and physically tipped-over, or has there been damage to the structural roots in the root zone due to the wind load?
A High winds pushing against the branches can uproot a tree, particularly those with heavy crowns, shallow roots, or those standing in waterlogged ground after a rainy summer. 

Q Is 50% or more of the crown (branches, twigs, leaves) intact?
A the 50% rule is a good rule of thumb as to whether or not the tree has enough leaves left to photosynthesize and survive, although other factors such as the time of year and the opportunity for watering also play a big role.

Q Other than the storm damage, is the tree basically healthy and vigorous?
A Of course a young, healthy tree stands the best chance of recovery. Past tree abuse, stressed conditions, poor maintenance, disease and pest problems can pre-weaken a tree, making it harder for it to recover. 

Q Has the leader been lost? (the main upward growing branch) Can a whip near the top of the tree be successfully trained to be the new leader? 
A To prevent a mis-shapen or deformed tree, a strong upright growth leader should remain viable and a twin-leader situation be avoided.

Limb ripped from trunk
Q Are major limbs broken?
A The larger the limbs lost, the harder it will be for the tree to recover. Trees canopies tend to grow to fill the space, and if limbs on one side are ripped off a young tree may look 2-dimensional for awhile. Evaluate if there are small branches or twigs already placed and "aimed" at the empty spot that can grow to fill the void.

Q Will the remaining branches be able to form a balanced, new branch structure?
 A Look for small twigs and branches aimed in the correct direction to elongate and fill in gaps in the crown, or make a 2-dimensional tree a nice, rounded 3-dimensional one after the passage of a few years. 

Old wound, healed over,
elliptical shape
Q How big are the wounds, and is the bark ripped?
A The larger the wound is in relation to the size of the limb, the less likely it will be to heal. Large wounds can be the point of entry for fungal and bacterial pathogens. Crabapple carefully ripped bark to an elliptical shape that will seal over with new bark within a couple of years. Rubber straps or bands can be used until the greenwood (cambium layer) knits together after storm damage (similar to grafting techniques).  

Crabapple LandscapeExperts can provide answers to these questions and evaluate the damage and the chances for repair and success for you.

Digging Deeper
A devastating storm hit London in October, 1987 blowing over millions of trees and lots of articles followed-up 25 years later. For example, Kew Gardens in London some drastic measures were used to upright and replant a few venerable trees while many were lost and the park replanted. 

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