Maybe the rooting issues have something to do with nematodes. Ultimate Flora might be nematode sensitive and that problem shows up in residential areas. There's a whole host of subsurface pests I have to think about now that Diazinon is no longer legal. Zoysia also grows better at a pH range between 6-7. Deviations from that range just makes the grass more sensitive and hard to keep nice. Zoysia is found wild in Asia in extreme environments in the wild. However, under those conditions, the grass is not mowed alt all and people certainly do not expect it to look nice. I keep on hearing about how zoysia will tolerate salt, alkaline soil, acid soil, low fertility and drought. I know that I am not in the business of torture testing the grass or trying to do the bare minimum for political or financial reasons.
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Benjamin Franklin 1775
Sell not virtue to purchase wealth, nor Liberty to purchase power.
Benjamin Franklin Poor Richard's Almanac1738