After removing a large branch, you might find that the callus doesn’t form evenly around the wound. The best way to fix this is to reopen the wound. Here’s an example of a wound created one year ago after removing a large branch on a black pine.
Old wound on Japanese black pine
The top half of the wound is healing well but the bottom half has died back a bit.
Good callus formation on the top half of the wound
To encourage callus to form, I use a chisel, knife and knob cutter to carve away deadwood until I see signs of live wood. In this case, the live wood is yellow and white.
Once I find the live wood, I expose a small amount of it all the way around the cut. The less that gets exposed, the better.
After reopening the wound
To keep the wound from drying out, I apply cut paste.
After applying cut paste
That’s it for now. I plan repeat the process next year as I expect the wound will close in about two years at the current rate.
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