Cities and towns may appropriate resources to be used under the direction of the tree warden in planting shade trees upon land adjoining public right of ways, at a distance not exceeding twenty (20) feet from the public ways, that will function as public trees by improving, protecting, shading or beautifying the right of way; provided, that the written consent of the owner of the adjoining land is first obtained.
R.I. Gen. Laws § 45-2-43