The best practice is to keep them at home where you can care for them until they go dormant. If you want those canvas bags to act as air pruning containers, they need to be elevated so air can get below the bag rather than setting them on a solid surface. I don't know what areas you are in or the climate in your area.They'll be in the middle of a field. I'm wondering if it would be better to plant in September ?
I would not recommend automatic watering for young chestnut seedlings. They are very sensitive to watering. They don't like wet feet. They like to be saturated and then dry out before being saturated again.I definitely would not plant them in the summer if you can’t water them frequently.
125 yards is not that far to run a hose/irrigation. Certainly possible if you’ve got good water pressure.
This answers one of my questions too, thanks...From looking at the picture, I'd guess those bags are nominally 3 gal. Those trees are far too small for the root ball to have filled those bags yet. When I was using 18s and the Rootmaker RB2 container system, I had pretty good success when planting when the root ball filled a 1 gal container (trees would be slightly bigger than those in the picture), but I had 100% success if I waited until they filled 3 gal RB2s before planting them.
When I was starting my chestnuts in the root pruning container system under lights in the winter, I would transplant from the 18s into 1 gal RB2s in mid-April about last threat of frost here in zone 7a. I would acclimate the 1 gal trees to natural sunlight on my deck. By early summer, most all trees would fill the 1 gals and be transplanted into 3 gals. By the end of the growing season, the best 50% of my trees would have filled the 3 gal RB2s and be ready for planting when dormant.So they will be planted in zone 8, southern catskills NY, consensus is plant when dormant, what about the option of keeping another winter and spring planting ?
I overwintered them once. Planted them in an old garden with netting around them and covered with a thick layer of mulch. Every tree did greatWhen I was starting my chestnuts in the root pruning container system under lights in the winter, I would transplant from the 18s into 1 gal RB2s in mid-April about last threat of frost here in zone 7a. I would acclimate the 1 gal trees to natural sunlight on my deck. By early summer, most all trees would fill the 1 gals and be transplanted into 3 gals. By the end of the growing season, the best 50% of my trees would have filled the 3 gal RB2s and be ready for planting when dormant.
I would overwinter the lower 50% and keep them on my deck for a second growing system and then plant them when dormant. It is important to make sure the roots don't freeze hard over winter and the tops don't get warm enough to break dormancy. Depending on your climate, some folks burry the containers or cover them with straw. I had a room in my house that I closed off from heat and opened the window. In my area that kept the roots from freezing and the tops from breaking dormancy. They do need some water during winter but not like when they are actively growing. I know folks who have used an unheated attached garage to overwinter tyrees.
I don't see any value in overwintering them to plant them in the spring unless you have some time constraint in the fall you don't have in the spring. Overwintering takes some effort and they are generally better off in the field during winter. The only reason I can see to overwinter them is if you they need a second growing season with TLC for the roots to fill a 3 gal root pruning container.