A tree struck by lightning: what the strike does, which trees it finds, and whether the tree lives

A tree struck by lightning can live for years, and how badly it is hurt depends on where the current ran. A strip of bark torn down one side of the trunk is a wound the tree can grow new wood over. A trunk blown apart can kill it outright, and a strike that burns the wood or roots inside can kill a tree with little damage on its bark. Since the outside is a poor guide, the verdict waits a full growing season.

What a strike does to the wood

Lightning follows the wettest path down a tree, and that path decides the damage. Where the center of the trunk holds the most moisture, the trunk can split or blow apart:

“Sometimes an entire trunk shatters, which can kill a tree outright, but even survivors are often severely disfigured, and the wounds become entry points for fungi and wood-boring beetles.” (Clemson Cooperative Extension, Lightning and Trees)

More often the current runs through the moist sapwood just under the bark. It heats the water there past boiling, and the steam blows the bark off in a strip, sometimes the whole length of the trunk. That strip is the lightning scar, and where the grain spirals it can wind around the trunk. Bark soaked by rain can carry the current down its outside with less damage. A lengthwise split that opens in a sudden deep cold is a frost crack instead.

Which trees lightning finds

Height makes trees natural lightning rods, and the tallest tree in a group, a lone tree and a tree beside water are the likelier targets. Ash, elm, oak, maple, poplar, pine and spruce are struck often. Beech, birch and holly are struck less often.

Of the trees we grow, cherrybark oak and longleaf pine are among the tallest, at up to 120 feet. Forest Service research on longleaf pine finds its odds of dying from lightning rise with height, and bark beetles gather in struck trees.

What to do after a strike

First deal with anything that could fall on people or property. Take down hanging limbs and jagged branches at once, cutting just outside the branch collar. Leave big limbs out of reach from the ground, and any tree near power lines, to a certified arborist.

Then wait, because the scar says little about the outcome:

“I have seen some trees with what appeared to be horrible damage, survive, and some that had very little visible damage, die.” (University of Arkansas Division of Agriculture, Lightning Damage)

Give the tree a full growing season, and judge it by how it leafs out next spring. Water it in dry spells, and hold off on bigger repairs until it shows it will live. Leave the wound unpainted, since paint can harbor insects and disease. The exception is an oak where oak wilt occurs: from April through July, cover any fresh wound at once with latex paint or shellac.

Keep watching for years. Struck trees draw insect pests, and lightning leaves pines open to engraver beetles. Decay fungi enter the wound too, and a tree that closes it usually goes on decaying inside.

A lightning protection system on a valued tree carries a strike to the ground through a rod above the crown, copper cable down the trunk and ground rods. It does not stop strikes, and an arborist designs and installs it.

If the tree lives, decay in the wound is the long-term question, and fungus on a tree is not a death sentence explains which signs matter. Blue Whale Trees answers questions about trees people already have through the support page. Say when the storm came, and photos of the whole tree and the scar can follow by email once we reply.

Common questions

Will a tree struck by lightning survive?

Some struck trees live for years with long scars, while a shattered trunk can kill one outright. The outcome is often hard to predict, so watch the tree through a full growing season before deciding.

Does lightning strike the same tree twice?

Yes, the same tree can be hit more than once. A tall lone tree or one beside water stays a likely target.

Should I cut down a tree struck by lightning?

Not at once, unless it threatens people or property. Remove hanging limbs, watch it through the next growing season, and let an arborist judge a large tree near a house.

Sources

• Lightning and Trees: Clemson Cooperative Extension, Home & Garden Information Center (Robert F. Polomski, 2022): the current following the moist sapwood, steam blowing off bark or sapwood, a shattered trunk killing a tree outright and wounds letting in fungi and wood-boring beetles, the tallest, solitary and waterside trees as likelier targets, the species struck often and less often, and what a lightning protection system is and who installs it.
• Lightning Damage: University of Maryland Extension, Home and Garden Information Center (2023): water under the bark heated past boiling and the steam blowing off strips of bark the length of the trunk, wood or roots burned without outward signs, waiting a full growing season, an arborist for a large tree or one near power lines, watering, and holding off on major repairs.
• When lightning strikes, is the tree out?: Purdue Extension, Indiana Yard and Garden (Rosie Lerner, 2019): moist tissue just inside the bark carrying the current, rain-soaked bark taking less damage, the same tree hit more than once, hanging limbs removed at once and large ones left to an arborist, trees living for years with extensive injury, their weakness to pests and decay over months or years, and an outcome that often cannot be predicted.
• Trees and Lightning: Purdue University Forestry and Natural Resources (Rita McKenzie, FNR-FAQ-9-W): trees as natural lightning rods because of their height, the moisture in the center that can blow a tree apart, spiral grain winding the scar, trees dying from small outward damage or living for years, water after a strike, and wound paint as a harbor for insects and disease.
• Lightning Damage: University of Arkansas Division of Agriculture, Cooperative Extension Service (2010): the quotation on badly and lightly damaged trees, judging a struck tree by how it leafs out in spring, and decay that goes on inside after the wound closes.
• Longleaf Pine: USDA Forest Service, Silvics of North America (Willis and others, 2026): the odds of death by lightning rising with tree height, and bark beetles associated with lightning-struck trees.
• Southern Pine Beetle or Pine Engraver or IPS Bark Beetle: Texas A&M Forest Service: lightning among the stresses that leave pines open to engraver beetle attack.
• Oak wilt in Minnesota: University of Minnesota Extension: covering a wound on an oak at once with latex paint or shellac from April through July, where oak wilt occurs.