1. Excavate the top 4-6 ins layer of dirt and fill back up with new topsoil of good quality.6 H1 n* j1 ? y# D3 I- b* U$ m1 V
2. Reduce the use of chemical fertilizer and use organic one instead.
/ y+ w: t* s. Q9 k; ^, ~$ wI 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.