i enjoy reading the posts of your further thinking on this. when you talk about your own experiences it’s interesting
i think this is one of the things where there’s too many variables to say yes or no, good or bad. like you say are you planting a thousand trees into nice damp soil, or trying to cram a single tree into sand or mud? and what time of year is it? and what kind of tree?
all of the little differences, think it matters a lot in the end whether you should or shouldn’t water in, and how much.
Honestly, my opinion is that if the soil is at a good moisture level watering plants in is never beneficial at all, as long as you firm the soil around the roots or root ball after planting. With my big bare root trees I end up walking with hard steps over the compost and mulch layer after planting to help everything stay in place and to firm up the mounds I always leave, although, in good soil, mounds not so tall that they don’t settle after a year.
I never plant my trees in a clay that will suffocate the roots after stamping down the soil. On the rare occasions when I’m dealing with that kind of soil, I make the mounds tall, mixing some of the clay soil with a sand-compost mix at and just below the ground level outside of the mound- that would be 5 of the 15 cubic feet of this mixture I bring. The rest creates the mound and is then covered by 5 cubic feet of compost and then the same of shredded wood mulch.
My orchards have a rep among landscape contractors in my region for establishing very quickly and that reputation has allowed me so sustain a viable business without having to advertise.
In my nursery, we don’t tamp down the soil so firmly because I only top them with wood chips and I’m not intentionally making mounds- quite the opposite- on my steep land we are usually creating slight wells for the trees after flattening the slope around the trees. Mounds require some stomping by my method. I never water any trees I plant directly after planting. In my nursery, the stonefruit often arrives from the nursery already beginning to grow. I am still curious if watering such trees in may be slightly beneficial, because no one seems to have ever researched the issue.
It is easy to say it all depends on a multiple of variables, but cannot think of a single one that makes any sense with trees fully dormant.