[Ozzello]

I have found the avg. pH in this area to be 7.2. (after 1000s of pH tests)
A bit alkaline for Zoysia (and most everything else you are growing) causing the grass/plants/trees to have difficulty with uptake of iron and other micro-nutrients.
I have had this discussion with the owners and managers of several of the larger lawn spray companies, and they either glaze over and change the subject, or give a song and dance about the experts back at the main office.

Example: The Florida DOT requires.. yes REQUIRES a target soil pH prior to even laying sod.
Yes, us old school native Floridians know how to grow grass here, have done so for over a century, and we don't have to spread poisons and fertilizer every 3 months to do it . Most of you have hired companies that are good at getting customers while overlooking the MOST IMPORTANT THING next to water.... soil acidity.

Save yourself a LOT of money...do a spot test... Spread a 1/2 pound of coffee in a 10x10 area of your lawn, note results within 4 weeks... you can thank me later.