Is there a preferred method to cable a tree for support? I have a large maple with 3 main trunks. One appears to be separating from the other two. One company wants to wrap a cable around all 3 trunks. I have seen pictures of other methods like drilling through the trunks and attaching a bolt on the outside of each one.
Cables are not wrapped around trunks but attached to large lag bolts. This is not something I would recommend to be done by anyone other than a professional. It is not easy and requires the right tension, location, and a trained hand at twisting individual strands in the cable. Any bolts that are driven through the two stems is done after the cables are all set in place. I would check to see if there is a Certified Arborist in your area that has experience with this. Certified arborists can be found at the International Society of Arboriculture site: https://www.treesaregood.org/findanarborist or at the Arboriculture Society of Michigan site: https://www.asm-isa.org/content.aspx?page_id=0&club_id=883139