This is a mulberry I grafted last year. It has always looked good. The branches still look very healthy. There were two branches that grew after being grafted and I left both. We had some really cold weather (for us) in March this year after the buds started swelling. I covered it with a tarp but the lower of the branches died back. I thought from the cold. So today I’m looking at this and I looks like the wood below the growing branch and above the graft is dead or dying. I really don’t see how the living branch is alive and growing. Photos taken encircling this area.
1 Like
Looks like a canker to me.
I don’t like that open wound, either. That’s an entrance for rot and anything to get in… but that’s probably not your fault. 
Dax
2 Likes
The future does not look promising for that tree. Perhaps you could air layer the top, or root some cuttings if you need to save the variety.
2 Likes
Yeah, air layer is a good idea for this time of year. I don’t know how well Oscar will root on cuttings. Anyone know? It’s not a big tree but does have some healthy limbs at present.