I live in zone 9b, South Texas. For two springs in a row, I've been having an issue whereby patches of my Zoysia grass starts turning red. Over time, the grass flattens and loses density. The blade tips themselves seem to lose their green and turn red. I'm fairly certain it's not rust fungus. There is no powdery substance on the blades and nothing "comes loose" when rubbing the grass. I've performed numerous troubleshooting and am at a loss for whats causing it:
- Ensured proper water coverage. Not only tested with cat food cans, but also drummed up a map and calculated water coverage. I do one deep water a week. No more. Also use a smart irrigation controller which automatically adjusts based on weather conditions.
- Mow every 7 days, never taking off anywhere near 1/3 of grass blades.
- Aerate and top dress with compost/sand once a year. I follow an organic fertilizing program. This year, I'm trying Milorganite. Last year did Medina/Milorganite mix.
- I've only used pre-emergent herbicide twice in 2 years. Otherwise I only hand pull weeds.
- The only insecticide I use is Grub-Ex. Haven't spread it yet this year.
- Tried spraying Ferilome Fungicide last year. It didn't work.
- I've even taken soil samples to ensure what my deficiencies are. Soil stats:
- pH 8.0
- Low N, P. High K
- High Mg, S, Zn
- Normal Mn, Cu
- Extra high Ca
- Extra low Na
I know my soil stats aren't the best, but I also have Bermuda grass and it never has this red bladed issue. Solely isolated to my Zoysia. Any ideas on what's happening would be greatly appreciated.