You certainly can graft apple onto apple. I don't know if you can graft quince onto apple. I have heard of fruit cocktail trees with different prunus: cherry, apricot, etc. You don't want to graft Japanese plums onto European plums. I don't know about peach or apricot. They are hard to grow on the wet side of the Cascades. I think they would take some of the same rootstock, but you should know which kind of plum you have first, in order to know what you can graft onto it. What kind of plum do you have?
John S
PDX OR

I’ve recently reassessed grafting to ‘Seedling Trees’… I’ve now lost two “Gravenstein apple” trees grafted to ‘seedlings’ that had sprouted along side the orchard. A special strain of Grav I’d meticulously pruned for decades -- they both died of what appears to be oak root rot/fungus. After a five year demise, eventually killing both trees, I will no longer advise folks simply graft onto seedlings because ‘they’re there.’

Although it appears a painfully slow process, I suggest (as you’ve apparently concluded) matching your desired cultivar (eventual fruiting variety) to a virus free ‘commercial’ rootstock with specific disease resistance and known dwarfing characteristics. If you’re a bit more impatient (like me), research your desired combination and purchase two to three year old trees from a reputable (often times mail-order) nursery.

I’ll still continue to Gorilla graft, but doing it to outlying forest or fence-line trees, not orchard trees expected to last a hundred-plus years…

You mean I don’t have to wear the hairy black suit

I can edit that… …though I’d always thought it referred to the simians, never knew there was a different version. Might it currently be called ‘insurgent grafting’?

…hummm ...now what orchard lore should I bump to make room for my newly learned word " title="Wink" />

John, “already existing trees” are OK to graft to …as long as they’re on a proven rootstock (that being the latest policy within ‘my orchard’). I’d long advised folks to graft anything that would work to anything growing… but after the painful loss of two special Gravenstein apple trees, originally grafted by my Great-uncle onto ‘chance seedlings’ …I've learned a painful lesson I’d not like others to experience.

The two trees were around 35 years old and had been meticulously pruned and cared for by me for 27 years - and slowly died. The first croaked around 5 years ago, and the second, about 8 feet away, died 3 years later. Never expecting them to be dying from ‘the roots up,’ their slow demise was obvious. As they were growing next to several native oaks… I’ll assume it was oak root rot – their roots simply rotted! It’s nothing I’ve seen happen to any other apple trees in my, or surrounding orchards.

Though my oldest trees are ‘Standards,’ they were of course grafted (perhaps by my great-grandfather), and likely to a known hardy rootstock, as opposed to ‘fruit produced’ seed stock.

Anyway, that’s my latest advice, and likely why virus free disease resistant rootstock has been bred… …and if used as the base or stock of a cultivar, should provide a healthy and stable grafting platform for anything compatible with that cultivar. – So Topwork away!

Fortunately, I never done what I was tempted to several years ago … after running my usual batches of apple juice and spreading the pressed pulp over a garden spot, nearly a hundred ‘beautiful’ seedling apple trees sprouted the following spring/summer. As I rotate between two garden spots, the ‘fallow’ plot with the seedlings eventually needed tilling in.

…that was painful, chewing up all those prime apple seedlings. One concern was the potential for a genetic improvement …though the odds for that aren’t so good, but the loss of ‘useable rootstock’ bothered me. I thought I'd leave a nice stand of them, bring home some apple scions from next springs exchange and “bench graft” them before digging to give away to ‘the needy’… As the painful experience with my two Gravenstein’s shown me, these trees would have looked great for years, likely growing into magnificent ‘standard’ apple trees in someone’s field or orchard … until some disease caught up with them…

I’d long ago topworked a half dozen apple seedlings on a neighbor’s hillside, for their horses. That worked fine, they’re too far from the house to have become ‘their orchard’ and if/when they naturally decline, the horses will be long gone ... if not the humans. But for some young energetic dude to acquire some land and graft over (like my one example) a bunch of seedling apples, likely forming their orchard around those trees and expecting them to last as long as ‘they should,’ only to lose them around a quarter their potential lifespan to something a $5 disease resistant rootstock and two years could have prevented …that’s the kind of bad news I now feel obligated to pass on to those thinking much the same as I, and my Great-uncle had… Dang!

…now there are a multitude of stories out there… like another neighbor that says the only way one can get European prunes to grow in this former commercial orchard area is to plant one by seed - then graft your desired cultivar onto that seedling. It’s worked for him, and after losing 3 prune trees to some disease he claims lives in the soil of former prune orchards - I’m tempted to give it a try. One of my favorite fruits are Italian prunes, of which I have none...

Others have said peaches grow fairly true to their seed and that ‘that’s’ a good way to establish a more hardy peach… It’s worked for another of my Uncles up The Gorge …though after losing around 5 peach trees I’m permanently off growing them…

I’ve got seedling cherry trees 80 feet high - competing with Douglas fir! I have grafted to smaller ones along the edge of the forest with producing cultivars… Last year I even grafted a number of producing cherry scions to a good stand of 2 & 3 year old seedlings for some friends, not expecting any problems …though a lack of aftercare and predator protection did most of them in

I know of a fantastic Persimmon Orchard grafted to ‘hand-plucked’ native seedlings from his Midwestern home state…

I guess I should mainly warn folks about grafting to seedling apple stock … and likely pear, too – though you don’t find that many seedling pear trees around. I’ve always assumed there was a good reason for all that disease resistance ‘commercial’ rootstock… Have I unmuddied the waters " title="Wink" />

[quote="John S":kuf7ald6] Italian prunes grow from cuttings. [/quote:kuf7ald6]
John, how common is that? …if that’s a commercial practice, no wonder I’ve lost three European prune trees – their roots were not resistant to ‘whatever’ is in the ground attacking plum roots…

I do know the two I planted were ‘store bought’ trees; would they have been on their own roots? If so, that could answer ‘that!’

…So, if I put an Italian prune (it feels unnatural referring to them as ‘plums’) on a (I’d have to look up what we last had at the show) ‘commercial rootstock’ bred for serious conditions – I could have one survive?