I have been planting avocados with limited success, and recently I decided it was because of my soil. I am taking a variety of steps now to address this. I am filling holes (with outlet channels) with drain rock and mounding soil on top, planting at the edge of a 4-foot retaining wall where there is drainage built in by design, and -- most recently -- experimenting with a giant square planter box walled with corrugated metal sheets. I have filled it with mulch and still plan to add heaps of sand and soil, with the expectation that the tree will sink in significantly. It's exhausting.
"Sandy loam, sandy loam! My kingdom for some sandy loam!"
Back to the unhappy white sapote. What should I treat the tree with? Is it obviously a fungus? Do I need to know what kind? Or is there an application that will cover a range of possibilities? I use virtually no purchased products for fertilizers or pest control, so I would benefit from a brand name or something.
And what if I just let it ride out the wet weather until it dries out?