Lightning Protection

Lightning Protection Systems

Each year, thousands of unprotected trees are struck by lightning throughout the United States. Many of those trees struck are in urban landscapes and can be a life-ending event for the tree, or even human. Can anything be done to protect your trees? YES! Lightning protection systems aren’t just for homes and large buildings. The same principals and many of the same materials can be applied to trees to provide them with a measure of protection against this powerful force.  

 

Which trees are good candidates for Lightning Protection Systems?

Arborists generally recommend protecting trees of historical significance and unusual value, shade trees within 10 feet of a structure, trees with branches overhanging buildings, tall trees in recreational or park areas, and those trees that are more likely to be struck due to location (e.g., isolated tree on a hill or pasture).  

 

Are certain species of trees more likely to be affected by lightning?

Yes. Due to size (taller trees are more likely to be struck), some differences in biology and physiology, and other factors certain trees are more susceptible to strikes. Below is a list of some common species in the eastern portion of the US and their susceptibility to lightning strikes. Not all areas of the country are equally affected by lightning strikes. Make sure lightning is common enough in your area to warrant the cost of installation and maintenance.

 

Species

Susceptibility

Maple

Moderate

Beech

Low

Ash

High

Tulip Poplar

Very High

Oak

High

Elm

Moderate

 

What is a Lightning Protection System?

Lightning protection systems are designed to provide a less resistant path to ground than the trunk of the tree. The system consists of a long section of copper extending from the top of the tree down to the ground and out to a metal plate or series of rods placed in the ground a distance from the tree which dissipates the charge into the surrounding soil. A terminal is attached to the top of the system to better attract lightning and is fastened to the tree using fasteners driven into the trunk of the tree every few feet down to the ground.

 

Mike Jolly of Asheville installing lightning protection

Is Lightning Protection expensive?

A good portion of the cost of a lightning protection system comes from the needed materials. The cost of installing a system will always be less than the cost to remove a struck tree. Lightning protection systems are an investment in your tree that can help protect it for years or decades to come. If some other pruning work is already being done to the tree it makes sense to explore the option of installing a system at the same time.

 

How can I tell if my tree has already been struck by lightning?

Sometimes people actually see their tree struck during a storm, but that’s not very common. Most only discover something is wrong the next morning. Lightning generally leaves some very clear signs that it stopped by for a visit. A long vertical scar running down the trunk of the tree and pieces of bark scattered around the yard are both very common. As the charge from the lightning travels down the tree towards the ground, the water in the tree’s cells heats rapidly causing an explosion, blowing the bark off the tree and leaving the scar.  

 

Lightning Struck Pine

What should I do if my tree has already been struck?  

Call an ISA Certified Arborist!  Not every lightning struck tree needs to be removed. Lightning is one of those semi-mystical forces of nature that’s hard to predict. Some struck trees are instantly killed while others linger on for years with suboptimal health, and others recover just fine and carry on. It’s always a good idea to have a qualified arborist inspect a struck tree to help determine the best course of action. Lightning can be such a powerful force that the structure of the tree is compromised, requiring its removal. Other times, some pruning and therapeutic/preventative treatments can be done to give the tree the best chance of recovery. Lightning struck trees should be re-inspected yearly to make sure things are going in the right direction.  

 
 

Thank You

You are now subscribed to our newsletter.