o.s. you need to get with someone
that has a good pto post auger and
get them to shoot you some 3'-4' holes
for your trees and fill with a good
grade of potting soil, put your tree
down and backfill the rest with potting
soil. that would get some running
room for the taproot on your young
trees. (maybe a couple of quarts of
pearlite too)
i have the opposite problem.
trade ya some sand for some clay