Here in zone 9 there is no problem grafting actively growing pear,
apple, and citrus scions, so long as they do not dry out in the process. If
the leaves are removed and the scion wrapped in parafilm, takes are nearly
100%. The same can be said for plums, with lesser success rates - I have no
experience with cherries.
Regards, Ethan
[NAFEX] Grafting Active Wood,
Dr. Ethan Natelson, 05/05/2003