I learned a lot from this post. I have been thinking of planting some trees but have no experience with it. One piece of advice I can give you on the Roundup / Glyphosate application - this is a non selective herbicide that if applied at enough times at even a low rate is more than capable of killing trees. Do not make contact with you trees (trunk or foliage) when spraying around them. I had a tree in my backyardtwo years agoon the line between myself and a neighbor. It had poison ivy growing up the trunk (the tree was big enough that I could not reach around it with both arms and touch). Not thinking, I sprayed the poison ivy with roundup to kill it. That tree is now dead as a hammer so be careful with the spraying.