Does a tree struck by lightning have to come down?
It depends on what kind of tree it is and where the strike went. A pine struck on a Hot Springs lot usually dies within the season even when it looks fine, so a struck pine standing over a house or a drive is normally a job for tree removal in Hot Springs. A struck oak or hickory often survives, and unless the trunk split, it can wait for a closer look next spring.
Lightning does not hit every tree the same way. Some strikes run down the outside of the bark and do little. Others travel through the wet wood just under the bark, boil the sap and blow a strip of bark off the trunk. A few go down into the roots and leave almost nothing to see above ground. The tree’s species decides how well it handles any of those, and on the ridges and lake shores around Hot Springs the tallest tree on a lot is usually a loblolly or shortleaf pine.
What does a lightning strike look like on a pine, and on an oak?
On most struck trees there is a long strip where the bark has been blown off, running down the trunk from high in the crown toward the ground. Everything worth checking can be seen from the yard. Do not climb the tree or lean a ladder on it.
- A strip of bare wood a few inches to a foot wide. On a pine it often follows the grain and spirals around the trunk. On an oak it tends to run straighter.
- Bark slabs, splinters and long shreds of wood on the ground around the base, sometimes thrown well out into the yard.
- A split down the trunk that goes deeper than the bark, with a gap you can see light or sky through from one side.
- A top that is blown out, broken off or hanging.
- Scorched or wilted needles in one part of a pine’s crown a few weeks after the storm.
Sometimes there is none of that. A strike that went into the ground through the roots can leave the trunk clean, and the first sign is a pine that starts to fade weeks or months later. A pine hit that way is still a struck pine, and it gets the same call as one with a scar.
Why does a struck pine so often die even when the scar is narrow?
The bare strip is only the part you can see. The heat of the strike also damages the thin living layer under the bark, the tissue that carries sugar down to the roots, well beyond the edges of the scar, and the shock stresses the whole tree at once. A narrow scar on a pine says little about how much of that layer survived.
A healthy pine pushes resin into any wound and seals it. Forest Service researchers studying struck loblolly pines found the strike cut that resin flow and dried out the inner bark, which left the trees open to southern pine beetle and the Ips engraver beetles. Keep an eye on the trunk of a struck pine through the fall, and the guide to what a beetle attack looks like on the trunk shows what to look for.
Can a struck oak or hickory be kept?
Often, yes. White oak, post oak and hickory take a strike better than pine does. They have no resin defense to lose, and the bark beetles that kill pines leave them alone. A hardwood walls off a wound and can keep growing around it for decades. What decides whether to keep one is the kind of damage.
A strip of bark blown off the side of an oak, with the trunk itself sound, is a wound the tree can live with. It will dry out and crack along the edges, and in a few years a ridge of new wood starts rolling in from both sides. A split through the trunk is a different tree. Once the wood is split, the two halves can move separately in the next storm, and decay gets into the center through the crack. An oak with a split trunk leaning over a house, a carport or a porch on one of the older streets off Whittington is a removal, however healthy the leaves look.
The other half of the answer comes in April. A struck hardwood can hold its leaves through the fall and still have lost part of its living layer, and the crown shows it at the next leaf-out. A tree that leafs out evenly is usually keeping the wound. A crown that stays bare on the struck side, or leafs out thin and late, is telling you how far the damage went.
Why do the same tall trees get hit?
Lightning tends to hit the tallest thing standing in the open, and height plus isolation is most of the story. On a Hot Springs lot that is the pine standing a full story above the roofline on a ridge-top lot, or the one left alone at the water’s edge on a Lake Hamilton or Lake Catherine lot, with nothing near it as tall.
A tree on a ridge top starts out higher than everything downhill of it, and a tree at the shoreline has nothing around it but flat water. They are often the trees people kept on purpose, for the shade or the look. A pine that has been struck once does not stop being the tallest thing on the hill, so the same tree, or the next tallest one when it is gone, is where the next strike tends to land.
Lightning protection systems for trees do exist, installed by arborists, and they are worth asking about for one valued tree in an exposed spot.
Should a struck tree come down now or after it leafs out in spring?
A struck pine standing over anything you care about should come down this fall or winter, while the wood is still sound and a climber can still go up it. A struck hardwood with no split in the trunk can wait for the spring leaf-out, when the crown will show how much of the tree the strike reached.
Waiting to see whether a struck pine dies usually means it does. The needles turn, the wood dries and checks, and the job that was a climb in October becomes one for a bucket truck or a crane. Taken down while it is still green and sound, a struck pine of 60 feet or more is priced like any other tall pine, $1,500 to $3,200 unless the lot calls for a crane, and the cost page lays out what a tall pine removal runs by height.
A struck pine with nothing in its reach, back in the woods behind the house, is a lower call, and the guide to which tree comes down first sorts it against the rest of the lot. Over a roof, a drive or the neighbor’s yard, taking a struck pine down belongs on this winter’s list.