How do I fix my problem apple tree? Grafting?

greg mosser wrote:can you get in there and actually see a spot where rootstock reaches past the scion? grafting could help, but i think it could be important to know what’s really going on there to begin with. a deep inspection in the fall after the leaves are gone could help. with pics, if you want help![/quote

I will wait until fall, and do that. Thank you for writing back so fast.

S Bengi wrote:If the hardy dwarfing rootstock is bearing fruits adnd you like the flavor. Then I think that you should just think of it as a multi-graft, cool fruit tree. I would 100% let it stay until the top half of the tree start bearing fruits. If you currently have a 2 in 1 apple tree now, and then you add yet another graft, wouldn't you end up with a 3 in 1 apple tree. There is nothing wrong with doing it, you might even end up becoming a professional grafter or end up making a 10 in 1 prunus tree as art. But it would be extra work.

S Bengi wrote:There might be multiple problems.
1) the top blossoms but doesn't bear, it might be too young or doesn't have a matching polinator that (A) have overlapping bloom time,  (B)matching triploid/diploid/etc dna, (C) good pollen

(2) The top of the might have gotten damaged (rabbit/rodent/machinery) and so it is sporting/suckering from the base. Or it could be that some borer/incest/fungus made its way into the tree

(3) It is technically that the blooms on the top part of the tree is also getting damaged by late frost?

You could just kill the non-producing top half and focus on just the bottom part, training it into a a tree. Another alternative could be that you have just invented a new bud-sport cultivar and so you could take a cutting of the producing part, root it and plan it over your garden, it seems to love your soil/climate?

S Bengi wrote:Ahh, now that you mentioned it it could be that it is too warm for the top part of the apple to set fruit, maybe there isn't enough chill hours for it to fruit, even though it will not die.

I might have used the wrong word when I said pollinator, I didn't mean bees/insect. I meant another apple tree nearby that is blooming at the same time that has pollen that makes it to the blossom on your tree and thus fertilize the ovaries/egg/seed thus making a fruit. Very few apple trees are self-fertile. And so it will need another apple tree nearby, unless it is a 2-in-1 multigraft apple tree.

Which apple cultivars do you have? Do you have any tasty apple trees in your neighborhood that you would take a cutting from to root or graft? Which cultivar is it.

Zone 10b in Cali sound like 20chill hours.  

greg mosser wrote:if the big fruit-less part really is an eruption of the rootstock, that’s the one that likely requires more chill hours than you get. if that turns out to be the case, a bit of grafting should definitely get you apples up there.