Do you think they will hit bottom in 2 and 3 gal containers by May?,... I could chill them for a bit out in the garage its not heated and doesnt get much light into it. They just had too much growth going on to keep in bags in the fridge, it was time to put them into something. I've got about 60 containers coming and need to still order another 100 3 gal for some apple tree grafts Im doing. I was just going to add an order of another 30 2 gal pots. Most of those container trees (Dunstans) people buy from the stores must be J rooted by the time they get sold I was hoping that the transplanting from the solos to pots would slow them down a bit.
6 flats are not going back into my fridge I can tell you that, for one they will not fit and two the wife would kill me, and 3 she informed me I will not be buying a "beer" fridge until after I build her a new house so... its going to be the garage or nothing.
Many trees, especially those with a large nut like chestnuts, put a lot of energy into that tap root and it does grow quickly. I don't know whether it will hit the bottom of the container by May or not. Just something to keep an eye on. When you buy containerized trees, Dunstan or otherwise, you deal with circling or j-hooking roots at planting time. You have to remove enough of the mix to prune them by hand. That can be a lot of root mass lost to pruning just before planting. It will slow the growth of a containerized tree and it will act more like a bare root tree which, as the saying goes, "the first year they sleep, the second they creep, and the third they leap". This is better than the alternative. The tree may grow great for a few years and look great above ground, but eventually those circling/j-hooking roots constrict themselves.
The approach that works for me is to start trees early indoors under lights with a root pruning container system. I keep them at home for one season and they are 6' tall or so when I field plant them in the fall. Nothing is free. I lose that deep tap root making the tree more susceptible to drought before it is well established. Fortunately in my area, the water table is not real deep and we get pretty reliable rain in the spring and fall/winter. I do get a lot faster growth this way and when invest in planting and protecting the tree, I confident it will thrive.
Another approach that works well for folks is direct seeding. This can be done in the fall letting mother nature do the cold stratification or you can cold stratify the nuts in the fridge and plant them in the spring before top growth begins. The upside is a natural tap root but growth is slower. Also, you need to protect the nuts when planted in the field and some simply won't germinate or grow well so you don't have an easy opportunity to cull to the best before planting.
You seem to be taking an in between approach. Presuming your tap root doesn't hit the bottom of the container and cause issues, you will have trees very similar to direct seeded. I'm not sure that small amount of time you are getting top growth under lights by May will be much advantage. It seems this in between method adds cost and time with little advantage over direct seeding.
Given that you plan to plant in May, I would direct seed them. My thought is to fill your existing cups with mix and put the nuts near the top and put them in the unheated garage with no light. You may want to put a small heater with an anti-freeze setting next to them cause you don't want them to freeze. You could transplant into your 3 gal containers when they arrive but I'd keep them in the garage. I'd plant and protect them in the field just like folks who direct seed.
Thanks,
Jack