Q: I want to hang a hammock between two sweetgum trees with trunks approximately twelve inches thick. If I put a screweye into the trunk, will it cause damage to the trees?
A: Will it cause damage to the tree?
I see young people with pierced tongues and wonder if the wound ever becomes infected. But some kids like them….. and since I wore an inside-out T-shirt all day recently, who am I to criticize fashion?
(I do find the clickety-clack of the stud on their teeth distracting when they talk. Perhaps someone will invent a stud with a bell inside so the tongue-pierced crowd will speak in musical tones.)
But to answer your question, yes, the pierced tree will be somewhat more prone to disease or insect invasion but, in a practical sense, it probably won’t be hurt.
I do have a mechanical suggestion. Screw eyes can pull loose. I’d recommend a long, 1/2 inch thread diameter, eyebolt. Companies that serve arborists sell these big eyebolts for tree repair work. Use an extended-shaft, five-eighths inch spade bit to drill a hole at the proper height through the tree.
Put a big washer under the nut on the far side of the tree. Hook your hammock to the eye of the bolt and swing the summer away.