1. Excavate the top 4-6 ins layer of dirt and fill back up with new topsoil of good quality. # E( n4 L8 C/ \2 \2. Reduce the use of chemical fertilizer and use organic one instead.
5 S% B# w4 d0 _6 N+ h3 d* [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.