How can I brace a weak trunk of a birch tree?

Asked September 13, 2020, 3:35 PM EDT

We have a birch tree in our back yard with 3 vertical trunks. 1 trunk is leaning and appears vulnerable to
any errant snow or wind storms. We are thinking it should be braced. We do not want to drill a whole in the "weak" trunk. Do you have some ideas on how we can provide support for this tree?

Denver County Colorado

1 Response

Before you make any decisions about cabling or bracing your birch tree, you should consult with a certified arborist. You can locate a certified arborist through the International Society of Arboriculture website: https://www.isa-arbor.com/ . The website has a search function to locate ISA certified arborists near your zip code. Some types of birch grow in a clump form similar to your photograph. This could be your tree's normal growth habit. Or, it could be a poor growth habit resulting in co-dominant stems. A certified arborist should be able to help you make that determination.

There are two ways to address co-dominant stems: pruning or support. An arborist may be able to develop a pruning program to eliminate the co-dominant stems and develop one main trunk. Pruning out the co-dominant stems could take several years. If your tree does need support, cabling is the most likely way to address it. I found a publication from Purdue University that discusses a no-drill cabling method called dynamic or soft cabling. I don't know if this alternative is common. I have only seen drill and metal cable support. I am attaching a link to the Purdue publication to provide more details:
https://www.extension.purdue.edu/extmedia/FNR/FNR-550-W.pdf .