Overheard a guy at the lumberyard talking about wound dressings

I was grabbing some hardware this morning and this older arborist was telling the clerk how he never seals cuts on trees anymore. Said he spent 20 years painting every pruning wound and then realized the tree does a better job on its own if you just make clean cuts. That got me thinking about all the times I've seen customers ask for wound paint because they think it's like putting a bandaid on. I've been guilty of using it too, mostly just to make the homeowner feel better. But after hearing that, I'm wondering if I've been causing more harm than good by trapping moisture in there. Has anyone else stopped using wound dressings completely or do you still use them for certain species like oaks in summer?

3 comments

3 Comments

sanchez.ivan5d agoMost Upvoted

Wait, is that true about oaks? I read a study somewhere that said oak trees actually release sap that seals wounds naturally within like 48 hours if you cut them right. I think that's why a lot of old school guys stopped using dressing on them completely. But I'm with you on the moisture thing - I had a buddy who painted cuts on his maples and then got rot inside a year later. The paint kept the bark wet and bugs got under it. Now he only uses it on storm damage with huge ragged tears, just to keep the bark from drying out too fast. I heard this one researcher say that trees have their own chemical response to cuts, and painting it basically confuses that process. Makes you wonder how much of the tree care industry is just old habits passing down.

wade_dixon5d ago

Got most of that right @sanchez.ivan but oaks are actually the opposite. They don't seal cuts fast, they're slow to compartmentalize and that's why you should never prune them in spring or summer when oak wilt is active. The sap flow you're talking about is more of a sugar maple thing. Oaks just kind of sit there with an open wound and that's why they rot so easy. The rest of what you said about paint doing more harm than good is spot on though.

jesse_smith105d ago

Yeah the "48 hours to seal" thing is a myth I've seen floating around. I've cut into oaks for years and they don't seal fast at all. You can come back a month later and the cut is still open and wet inside. That's exactly why oak wilt spreads so fast through pruning cuts in spring. The tree just sits there with an open wound for weeks. I only prune oaks in late fall or winter when the beetles that carry wilt are gone. And you're right about the paint causing issues, I stopped using it on everything except big storm tears where the bark is peeled back and needs to stay moist while it calluses over.