I don't need it to last that long. My "baby trees" should be big enough in less than 5 years for me to remove the fencing AND I may want to plant some herbs/flowers at the base, which is hard to do with the wire fencing. Bear in mind that these trees are growing Next to my chicken's run so I see them every day. The metal fence posts are old and none of them has the sharp "v" on them. They should come out of the ground pretty easily, just like tent stakes, where you pound E-W-N-S until you can pull them out. I remember seeing gardeners who "root prune" their fruit trees so I am not worried about future root damage.
https://homeguides.sfgate.com/prune-tree-roots-stimulate-growth-57774.html
They are now 2 inches in diameter. When they get to 4 inches diameter I COULD root prune 20 inches from the trunk, which is inside of my posts.
https://www.starkbros.com/growing-guide/article/stages-of-apple-tree-growth
I may remove the metal posts next year.
The wooden posts will rot into the ground and They should be solid by next year, since our base soil is clay. That will give me something to tie to, should I need to do so to keep their trunks growing straight.
They are safe enough next to the trees. They were cut last October and won't grow any roots since they sat out in the weather for almost 6 months.
I planted my Montmorency Cherry trees in what was Then my South Pasture and their trunks are about 8 inches in diameter this year. I didn't protect
them, but soon after planting we refenced and they became trees in my "inner sanctum", the fenced in area in front of, and to the south of my barn and 2 outbuildings.
We have been getting heavy rains. I only deep soaked the two of them once bc I had planted too deep and needed to get them both higher bc of the root graft. I see buds growing on both. I know to keep them watered, but I will let them dry out some this summer so that they reach down with their roots.
I DID my research and NOBODY had any advice as to solving my problem: growing baby (2yo) apple trees where my horses SOMEtimes graze. Horses will get excited and run where they don't normally get turned out. They KNOW that it is special when I let them graze there. I like it bc it saves me gas and mowing time. Right now they are fighting their leads when I turn them out from their stalls bc they want the grass. Also, Spring grass can founder your horses in a
large pasture. They won't founder on 1/4 acre.
I was just really happy that both baby apple trees are growing. Remember, I planted one directly on the spot where a GD apple tree had died some 7-8 years ago, and the trunk finally rotted out in 2018. Success!!!
I always appreciate your concerns and advice.