Will a Tree Struck by Lightning Die?
Some trees die from a lightning strike, and many survive, and there is no reliable way to tell which on the day it happens. Nebraska Extension notes that a struck tree, even one with little apparent damage, may not survive, while others live through what looks like terrible damage. Unless the trunk or major branches are severely cracked or split, or broken limbs are hanging in the canopy, Nebraska Extension recommends a wait-and-see approach to find out whether the tree recovers.
The damage you can see is not the full picture. In a 1983 article in the Journal of Arboriculture, published by the International Society of Arboriculture, Ernest DeRosa wrote that in many cases a trunk shows only minimal damage, such as cracking or peeling bark, while the roots have suffered considerable damage. This post covers how to read the signs after a strike, when a tree has to come down right away, how long to wait on the rest, and what care helps a survivor.
What Does Lightning Do to a Tree?
Lightning damage follows the moisture inside the tree. Purdue University's Forestry and Natural Resources extension explains that when moisture is concentrated in the layer between the bark and the wood, the strike follows that channel and causes an explosive separation of the bark. When the moisture sits deeper, the tree can split apart from within.
The results range widely. DeRosa describes effects from no noticeable damage to total destruction by splitting, explosion or burning. The Alabama Cooperative Extension System adds two injuries that are easy to miss:
Stripped bark leaves the wood underneath open to decay and insects.
Damaged water- and sap-conducting vessels put the tree under drought-like stress.
Which Trees Get Struck Most Often?
DeRosa lists oak, elm, maple, poplar, ash, spruce, fir, pine and tuliptree among the trees frequently struck. Beech, birch and horsechestnut seem to be rarely struck, which he linked to their smooth bark holding moisture during storms and conducting the charge along the outside of the tree.
For Western Pennsylvania yards, the frequently struck list includes many of the most common large shade trees. If you have a big oak, maple or tuliptree near the house, it belongs on the short list of trees to check after a close strike.
When Does a Struck Tree Need to Come Down Right Away?
Nebraska Extension draws the line clearly. The wait-and-see approach does not apply to a tree with severely cracked or split branches or trunk, or with broken branches hanging in the canopy. Those trees need attention now, before anyone parks, plays or works beneath them.
Signs that call for a professional look before anyone works near the tree:
A crack running down the trunk
A trunk or large limb split open
Broken branches caught in the crown
Any contact with power lines, which is a job for the utility first
If a struck tree threatens a house, vehicle or driveway, treat it as emergency work. Our guide to whether cracked tree trunks mean immediate removal explains how crews judge a split trunk, and tree damage after storms: assessment and emergency response walks through what happens after the call.
How Long Should You Wait Before Deciding?
For a tree without severe structural damage, patience pays off. The Alabama Cooperative Extension System advises waiting several weeks before removing or even pruning a struck tree, so the damage has time to become evident. DeRosa went further and recommended waiting about a year to judge the tree's overall response before treatment.
Those timelines work together. A few weeks tells you how the tree is responding in the short term. A full growing season gives hidden root damage, the kind DeRosa described, time to show up in the crown as thinning leaves or dieback.
Pines are the exception to waiting long. The Alabama Extension notes that Ips pine beetle attacks are common in the days or weeks after a strike and can quickly weaken and kill the tree, so a struck pine needs a close eye.
How Can You Help a Struck Tree Recover?
The care is simple, and part of it is about what not to do:
Water during dry spells. Nebraska Extension, the Alabama Extension, and Purdue all recommend watering, because a damaged tree is already short on water.
Skip the wound paint. Purdue says painting the lightning crack with wound paint is not a recommended practice.
Clean up loose bark and broken branches. Nebraska Extension recommends trimming loose bark with a sharp knife and pruning broken branches.
Watch for secondary problems. Purdue notes that a tree surviving a strike often succumbs later to insects and disease.
A long-term concern is decay. The Alabama extension warns that lightning scars with no bark across more than one-third of the trunk diameter are likely to cause significant future decay, making the tree prone to structural problems and failure over time. A tree that keeps its leaves can still be weakening inside, and our post on signs a tree is rotting inside covers what to watch for in the years after a strike.
Can You Protect a Valuable Tree From Lightning?
For a valuable tree, Purdue describes a lightning protection system made of copper cables attached to the tree's highest branches and grounded at a safe distance from the tree. It is an option worth pricing for a large landmark tree you cannot imagine replacing.
Insurance is a separate question. If a struck tree damaged your home, garage, or fence, call your insurer before cleanup begins, and read our guide on how to file an insurance claim for storm tree damage. Coverage depends on your policy, so your insurer is the one who can tell you what applies.
FAQ
How do I know if my tree was struck by lightning?
Look for bark that has been blown off the trunk, often in a strip, or a fresh crack in the wood. Purdue describes strikes that cause an explosive separation of the bark, and DeRosa notes that some strikes leave only minor trunk damage, such as cracking or peeling bark.
Should I cut down a tree right after it is struck?
Only if it is severely cracked or split or has broken limbs hanging in the canopy, according to Nebraska Extension. Otherwise, the Alabama Cooperative Extension System suggests waiting several weeks before removing or pruning it.
Can a tree die months after a lightning strike?
Yes. Purdue explains that some trees die soon after seemingly small damage while others live for years, and survivors often decline later from insects and disease. Root damage that does not show on the trunk can also catch up with the tree.
Should I seal the wound?
No. Purdue says painting a lightning crack with wound paint is not recommended.
Should I fertilize a tree after a lightning strike?
Sources differ on this, so start with water. DeRosa's 1983 recommendations included phosphorus-rich, low-nitrogen fertilizer along with watering, while the more recent Nebraska and Alabama extension guidance focuses on watering during dry periods and pruning broken branches.
Which trees are least likely to be struck?
DeRosa found beech, birch, and horsechestnut are rarely struck.
Emergency and Storm Tree Service From Brinko Tree Service
Brinko Tree Service, based at 1010 Sunset Blvd in Harrison City, has nearly 20 years of experience with trees across Westmoreland and Allegheny Counties. The team offers 24/7 emergency tree removal and storm damage cleanup, including hazard assessments after storms to check trees for structural damage and instability. When a struck tree is split or failing, Brinko provides safe tree removal, stump grinding and debris cleanup. The company is fully licensed and insured, follows OSHA and ANSI safety regulations with an OSHA safety site supervisor on every job site, and offers free estimates.
Visit Brinko Tree Service or call 412-373-7450 today. Contact us for more information.
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