1. Excavate the top 4-6 ins layer of dirt and fill back up with new topsoil of good quality. ; Z* s' C$ }2 A$ b2. Reduce the use of chemical fertilizer and use organic one instead.
7 ^7 T( P& c! g& u( b$ I' [# GI 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.