I’ve been growing a small starter-orchard in my rooftop garden for a few years now, but we’ve finally moved to a house with a yard!
I’m plotting out where the trees are going to end up, and looking for any advice on transplanting them from their pots. I’ve planted containerized plants/trees from nursery stock before, of course, but these have made a home in their 30-gallon pots for 3-4 years at this point; they’re young but strong, and some have even started fruiting reliably. I don’t want to be foolhardy and treat it the same as plugging a new sapling in.
My instinct is to wait until November or so, letting them go mostly dormant before moving. A part of me wants to just ease them out of their pots with as little fuss as possible, avoiding any transplant shock at all.
Another part is tempted to treat them more like a “bare root”, tease their roots apart and do a light root-prune to freshen and stimulate them in their new location, as they’ve been stuck in their same spot for most of their life.
Fruit trees don’t tend to strangle themselves with rootbind. However, I agree with your thoughtful strategy of waiting to transplant. What I’d do is plant the pots now where you are putting them permanently so some root might grow out of them during Aug and Sept which might pull freely out of the pots in Nov when trees are dormant.
I don’t cut balls open but any winding roots just inside pots I pull free and spread into the new soil when I do the installation during dormancy. I will even use landscape staples or rocks to hold roots in an outstretched position. I’ve noticed that trees respond better than when I ignore the state of the roots and just take them out of pots and put them into the ground when they are in leaf. Half the depth of the pots is adequate and will stop them from blowing over from normal winds.
If you mess with the roots while they are holding crop, they will likely drop the crop from the stress.
Wait for dormancy, do it in the spring before the trees wake up.
And don’t tease the roots, rip as needed. The more loose and downright broken you get them the better the tree will adapt.
Think of roots like the branches above; you got old tired roots which do very little for the tree, you do not want to try and save them as if the life of the tree depended on it because that would only drag the tree down. A heavy pruning will promote new growth that will make the tree adapt the best. It will also self regulate; putting up as much top growth as it can support. It may look stunted but trust the tree to be doing what needs doing.
Also transfer shock is not necessarily a bad thing. A good shock will send the tree into adaptation mode; As I said top growth may be subpar for the entire year but in the long run the tree will be better off for it. If on the other hand you ever so gently put the tree on its new place that nothing chances and water it too diligently, the tree will have no reason to actually push new root growth.