questionable fungus in zoysia

Question: Innovation zoysia put down in July 2022.  Was terrible last spring after winter kill but did well by July-Sept.  Now it has what I wonder is fungus.  I put down fungicide Lebanon Eagle 0.62 in late March and repeated 2 weeks later.  Does not seem to be helping much.  Advice?  Thanks.

responder: Answered by theHome and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied April 29, 2024, 11:31 AM EDT
response: It is normal for your Zoysia lawn to look tan and dry right now. Zoysia is a different type of grass than what is the recommended and commonly used grasses for lawns in most of Maryland, which is turf-type tall fescue. Most lawn grasses here are what are termed 'cool season' grasses. They green up and start to grow early in the spring. In the hottest part of summer, when we lack rain, it slows down and is best allowed to go dormant, but it will green up again once there is rain and cooler weather.  Zoysia, on the other hand, is a southern 'warm-season' grass. It doesn't  turn green and start growing again until well into May.  Here is our page on Zoysia lawns and their care:  https://extension.umd.edu/resource/planting-and-maintaining-zoysia-lawn/   Christine

responder: The Question Asker Replied April 29, 2024, 2:16 PM EDT
response: Thanks so much. The brown/dormant I can understand, I just want to make sure the rust is not a fungus. Can you tell anything from the attached picture? And if it is then should the applications of Lebanon Eagle 0.62 Fungicide take care of it and/or will the spring green up just crowd it out. Thanks again for your help. On Mon, Apr 29, 2024, 11:31 AM Ask Extension <<personal data hidden>> wrote:

responder: Answered by theHome and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied April 29, 2024, 2:37 PM EDT
response: We can't see any detail from your photo. Zoysia can't have a fungus (rust is a fungus) right now because it is dormant. Do you have tall fescue mixed in with your zoysia? Can you give us any more information and a better photo of what you are seeing? We'd be happy to look again.

responder: The Question Asker Replied April 29, 2024, 4:06 PM EDT
response: Thanks.  I am not sure how to get a better photo. There is no fescue in with the zoysia.  It was Innovation zoysia and the sod was laid in July 2022.  I can assure you there is a lot of green in the zoysia and it has been turning green for several weeks.  Some is still dormant, yes, but there is a lot of green. How do I get a better photo?  The rust and green and brown are quite obvious in the picture I see.  I appreciate your time and effort trying to help me with this.   On Mon, Apr 29, 2024 at 2:37 PM Ask Extension <<personal data hidden>> wrote:

responder: The Question Asker Replied April 29, 2024, 4:17 PM EDT
response: I'll add 2 more pics to see if the damaged zoysia is any clearer.  Let me know.  Thanks. On Mon, Apr 29, 2024 at 2:37 PM Ask Extension <<personal data hidden>> wrote:

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied April 30, 2024, 11:17 AM EDT
response: Thank you for the additional information and photo, though unfortunately we did not receive the two files you sent afterwards (image file names ending in -775 and -502). Can you retry sending them?  Rust fungus is named for the orange spore pustules that appear on infected leaves. The spores might only be present and visible once an infection has progressed to a certain stage and environmental conditions are right for spore production (generally when it's wet from rain or dew, or if the grass is irrigated often). You would be looking for (or sharing a close-up photo of, for confirmation) the symptoms pictured in the lead image on our Rust on Lawns page. When walking through a rust-infested patch of lawn, the spores can stain your shoes orange.  Zoysia can contract rust, but we don't have information about Innovation and its resistance (if any) to that particular fungal infection. While the fungicide you chose should help to suppress new infections (it cannot cure any existing outbreaks or leaf damage), it would need reapplication throughout much of the growing season, since rust on grasses can go through several infection cycles. Since this might be prohibitively expensive, the long-term solution may be to manage the nitrogen fertilization of the zoysia differently (if you haven't been following the recommended rate, for instance) since stressed and under-nourished zoysia is more vulnerable to diseases.  If weather conditions become drier for the summer, and if the grass is not irrigated too often, the rust infection cycle should subside on its own unless mornings are still very dewy, since leaf wetness allows spores to infect more easily. If rust is not present and no other fungus is responsible for any leaf dieback, then the fungicide won't provide any benefit.  If you have trouble getting a close-up photo of symptomatic grass blades, you can also try bringing a sample (with photos like those you shared here) to your local county Extension office or to a Master Gardener plant clinic in your area. They will need to see grass that is suspected of being infected but not totally dead yet, since little can be diagnosed from already-dead, brown/dry blades.  Miri

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied April 30, 2024, 1:04 PM EDT
response: One of our turf specialists looked at your photos and is fairly certain the zoysia has a disease called "Large Patch" instead of rust, which he feels would not be that prevalent this early in the season. Large Patch is caused by the same fungal species (though a different strain of it) as Brown Patch in fescue lawns. He advises that, should treatment remain necessary (that is, if the grass doesn't outgrow the damage by then), a fungicide application made around September would help suppress infection going forward. In the meantime, he says you can mow low (to about 2 to 2.5" high) to improve the air circulation through the zoysia grass blades to encourage them to warm-up faster and stay drier so any leaf wetness is less likely to contribute to further re-infection.  He also suggests fertilizing (if you haven't already) with about a third of a pound of nitrogen (per thousand square feet of lawn) now, again in late May, and once more in late June to push more new growth in the zoysia. This should help both with rust (if present) and outgrowing any Large Patch damage.  The brown areas also resemble residual drought damage he thinks, so perhaps some areas that didn't fare as well have some obstruction to drainage or more compaction impeding moisture absorption or root growth. The bits of green regrowth visible amid those brown swaths is encouraging, though, and suggests that recovery in those areas may be possible.  Miri

responder: The Question Asker Replied April 30, 2024, 2:11 PM EDT
response: Thanks so much for your help. I will be doing those things you suggested and am optimistic those things will help. Thanks, again.On Tue, Apr 30, 2024, 1:04 PM Ask Extension <<personal data hidden>> wrote:

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied April 30, 2024, 2:29 PM EDT
response: You're welcome!