N.H. Rev. Stat. § 231:149
Any young shade or ornamental tree planted within the limits of a public highway by the tree wardens or by any other person or persons, with the approval of the governing body, or any young seedling tree or sprout left within the limits of the highway as specified in RSA 231:150 and designated by the tree warden to be preserved for its future value as a shade tree, shall become the property of the municipality; provided, that the abutting landowner, having been notified of the intention of the municipality to take and preserve such young tree, shall make no written objection to the tree warden within 30 days from the date of such notification.
RSA 231:149
1901, 98:7. 1915, 138:1. 1917, 62:1. PL 93 :30. RL 109:30. 1945, 188:1, part 23:9. RSA 253:9. 1981, 87:1, eff. April 20, 1981. 2012, 24:8, eff. May 2, 2012.