to seal or not to seal -- if so, with what?

Asked August 10, 2017, 5:09 PM EDT

I'm treating a 6-foot tree whose main trunk broke. I know to make a clean, smooth cut across the broken area. My question is: should I seal it or not? If so, with what? I find information online for and against sealing and for and against pruning sealer. Could I use polyurethane varnish instead? Or is shellac best?

Baltimore County Maryland

1 Response

Wound dressing/pruning sealer is no longer recommended for pruning cuts. Research proved that it actually slowed down the tree's healing process.

The most important thing you can do is be sure that you cut at a slight angle so water does not accumulate. When pruning off a branch, be sure to cut right at the branch collar and leave the branch collar (the raised area where the branch goes into the trunk or larger branch) and do not leave a stub.

For help with pruning, here is our pruning fact sheet: http://extension.umd.edu/sites/extension.umd.edu/files/_images/programs/hgic/Publications/HG84_Pruni...

ECN