I've been fascinated by the possibility of interspecies grafts this last year, mainly as a means of converting established landscaping trees into fruit bearing trees. I know that there are some reported, but its hard to find information on what's been tried and failed. Stonefruits and citrus have lots of compatibilities. But what about other subtropicals and tropicals?
I have 3 experiments going right now, one of which looks promising. Should be able to report in a couple months.
I'd be interested in hearing your stories.
