1. Excavate the top 4-6 ins layer of dirt and fill back up with new topsoil of good quality./ H4 T' x A9 w; F+ X
2. Reduce the use of chemical fertilizer and use organic one instead.
" C, Y" }7 ~) [: H; M
I should tell a bobcat is required if you wanna do the whole front/back yard OR just spot-excavation (dig a bigger and deeper than normal hole, dump the old dirt and back fill w/ good topsoil when you want to plant a new tree) if you gonna do the job yourself.