I asked a question about marking trails and one of the answers suggested nailing markers to the trees. Does this damage the trees? I'm mostly concerned about long-term infection or rot that will eventually kill the tree.

  • I used to do ecological surveys and I have seen trees that were marked with nails in the 1950's that are doing just fine, but I suspect it depends on the tree type - there are Yew trees in the UK and Europe that have been carved out inside and rooms installed for several hundred years, and those are still alive. Like this one. It even has a cannonball embedded in the tree from the English Civil War (1642-1651).
    – bob1
    Feb 20, 2020 at 19:55
  • I think that copper nails are harmful to trees, but I don't have a source, and I'm unwilling to answer with speculation. Feb 20, 2020 at 20:15
  • Not the same thing, but I once talked to a guy harvesting pine tar (which involves debarking parts of the tree), and he told me the fir trees he works with are doing quite well with it. And that's much more of a mutilation, at least superficially. Feb 21, 2020 at 18:43

2 Answers 2


It can hurt the tree, and allow disease to enter through the hole. The other reason not to use nails in trees is for humans, cutting into a nail with a chainsaw can be dangerous.

It probably won't kill the tree right away, there are living trees in Yosemite that were marked with large blazes by the Calvary in the early part of the 1900s and that didn't kill them.

Also see,


Trees can be remarkably resilient. As explained by Davey, a tree care company:

Healthy trees are tough, and when they’re drilled with a nail or screw, they’ll start a process called compartmentalization, which means they naturally heal the area around the wound and protect the rest of the tree from potential infection. So, for the best stability, choose a healthy, strong tree.

This is why tapping maple trees for syrup each year leaves virtually all of them completely healthy.

There is a more practical reason why putting nails in trees is frowned upon, and that's because of dangers that can arise when felling or milling them after the tree has grown around the metal fixture.

  • ... as well as the fact nails (or bullets/shrapnel like e.g. in some European regions where two WWs took place, see e.g. wa.de/hamm/uentrop-ort370525/…) can make that trunk practically worthless. Prime example would be a steel (iron) nail in an oak trunk, which will cause a dark stain due to the reaction of iron with gallic acid. Feb 22, 2020 at 14:52

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