I was in my orchard yesterday and took some photos of thousands of apple seedlings that started growing from a bagasse (waist that’s thrown away after apple juice production).
I was wondering if it can be used successfully for a proper rootstock for grafting and how to slingshot it’s growing rate.
Yes, you can use them as rootstock. However, they will probably almost all be standard size trees and take a while to bear. They’ll be all over the map on things like disease resistance, cold hardiness, etc. If you’re ok with all those caveats, they are an excellent source of cheap/free rootstock. I have a friend who did this with seedlings that came up from her pomace. She had pretty good results, but sometimes wishes she had gone with named rootstocks.
Terminology correction…the leftover material after pressing apples for juice, cider, etc., is pomace.
Baghasse is the fibrous material left over after milling/pressing sugarcane.
The apples that John Chapman (Johnny Appleseed) grew/sold/planted were seedlings from the Eastern cider mills. IIRC, as an Anabaptist, he was religiously averse to the act of grafting.
But, as jcg has indicated, your seedlings will be a mixed bag, genetically, but some will absolutely make fine standard rootstocks.
There are some threads on here about branch bending, bark inversion, girdling and other nifty/nefarious tricks to induce dwarfing and early fruiting. They’d all be worth looking in to, but there are no guarantees from what I understand.
If selecting for fruit qualities, your probably best off grafting (chip bud for example) to dwarf stock. For earlier production. Or grafting to existing tree’s (dwarf or already bearing)
If you need rootstocks. I’d usually stick to know cloned stock. Or for seedlings of a known variety. The apples selected for fruit qualities are just that. selected for fruit qualities, and thus usually have poorer root qualities. Although not guaranteed.
The cloned stock however has specifically been selected for it’s good root properties.
Only reason i see to sow your own, is if you believe the taproot to be incredible important (means you should avoid transplanting though)
Or if you have to grow them for the lowest possible expense.
I personally think it’s always “worth” it to use a known rootstock. If needed stool it yourself.
And if looking for a new variety, it’s usually “best” if you know 1 of if not both of the parents.