branch stubs are turning black

Asked April 16, 2017, 10:22 PM EDT

I have apple trees and where I have cut branches the area around the cut turns black. Is this a problem? Do these apple trees need to be treated with something?

Frederick County Maryland

1 Response

The black coloration you see is not decay. You'll notice that the color extends below the cut, where sap dripped from the pruning cuts. The pruning cut looks like it has healed well. Sometimes harmless fungi grow in the sweet sap that oozes out to heal the cut, and this may have colored the area when it dried.

Never treat pruning cuts with 'wound dressing'. Research has shown that these products actually slow down the tree's healing process.