OK, keep them moist, I am guessing you are talking about the young trees as well as the seeds. Carry water to them for awhile until the get very well established and well rooted. You guys know that I go with the no work theory of gardening and I normally let the Good Lord do my watering for me around here and help Him along a bit with heavy mulch. It is a distance from the house to the garden and the orchard and water is heavy, so I do not carry that much of it by hand. Filling buckets and putting them into my cart to move them to the trees would be a little easier, but the water slops out of the buckets and spills all over the place. My normal way of getting water to the garden has been to fill 2 two gallon watering cans, one for each hand so that I am balanced, and walk up to the garden or the butterfly garden and water the newly planted flowers and garden plants. Each plant gets 3 to 5 sec of water poured directly on the young plant. That process does not normally last very long, maybe 2 days or so for the garden, a couple more for the flowers and then I consider them established. Once a plant is established here on the hill its on its own, survival of the fittest you might say. Trees are a bit different, they cost more, they are a lot more work to plant, and if they survive and grow you get the benefits for many, many years. So putting some extra work into getting a tree established and making sure that it will thrive is worth the effort to me. I was told years ago that when planting a tree you dig a $10 hole for a $5 tree. Now that trees are $20 I guess I need to dig a $40 hole.
Of course my time is more valuable now than it used to be, so I guess every thing has gone up with inflation,
Bottom line is that you put a lot more work into planting a tree, so giving it some water to insure that it will make it the 1st year makes sense.
Never doubt that a small group of dedicated people can change the world, indeed it is the only thing that ever has.