Hello, I have a Satsuma Plum that is very healthy but doesn't produce much fruit and would like to add more scions to it. I successfully grafted a Beauty scion onto it but everything was just breaking dormancy. I would say that 85% of the Satsuma Plum has fully leafed out. I just found a possible source for getting a few more free plum scions right now.

Is it too late to graft? If not, any advice on grafting onto branches that are already leafed out? Should I graft onto new wood from the past 2 months of growth or should I stick with last year's wood? Should I remove the leaves on the donor branches?

I can only do cleft grafts as all the other grafts I've never had success with.

Thanks!