Brown Patch Zoysia - Southern Maryland - Ask Extension
Hi, UMD Garden Experts! I believe I have a type of Fungus in our Zoysia lawn. This is the second year that we have had brown patches in various places...
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Brown Patch Zoysia - Southern Maryland #788684
Asked April 30, 2022, 7:24 PM EDT
Hi, UMD Garden Experts!
I believe I have a type of Fungus in our Zoysia lawn. This is the second year that we have had brown patches in various places. The first year was not as bad as this year. It appears to have spread into not only the back, but front lawn this time. I did not treat it with fungicide until this year (roughly 3 weeks ago). How soon after treating with fungicide will it be safe to fertilize?
Need your help!!
Thank you in advance,
Clyde
Prince George's County Maryland
Expert Response
Hello Clyde,
We consulted with one of our turf experts as this was an uncommon symptom in zoysia. Based on the photo, he believes this is a disease called Large Patch, which is caused by (potentially) different fungi than those responsible for Brown Patch, though they are all in the same genus of Rhizoctonia.
Not all fungicides will suppress these fungi, and the timing of application can be important for good treatment efficacy. Typically this infection begins in autumn, so sprays attempting to cure existing infection may not work (or at least will not work quickly). Preventative applications made in autumn, before symptoms appear, should be more successful, though repeat applications will likely be needed. (You'll have to see what the product label says about timing and intervals.)
Fortunately, this infection tends to leave turf crowns (the origin point of growth) and horizontally-spreading stems intact. Since zoysia is a warm-season grass, it should begin to regrow vigorously once our weather remains warm, and it may be able to self-repair by itself. The fungicide you've already applied might halt some fungal spread among the still-green growth, but the damage has already been done to the brown foliage.
Conditions conducive to infection include any degree of shade and areas that collect extra water (such as from a roof downspout outlet) that don't drain well. Core-aeration this summer might alleviate compaction that is slowing drainage; otherwise, locations in the yard that are not easily altered to improve conditions for the turf should be converted to alternative groundcovers so this disease is not a recurring risk.
Fungicide active ingredients that should provide the best control for Large Patch include azoxystrobin, flutolanil, and tebuconazole. Not all may be available to the general public, but can be applied by pesticide applicators via a lawn-care company. Given the cost of some fungicides and the relatively small volume used per application, the most affordable option may be to hire an applicator. You may need to have applications made around September and again in March, but verify the timing instructions specific to each individual pesticide product; even those sharing the same active ingredient may not have the same application instructions. Similarly, make sure a fungicide that contains one of those active ingredients is labeled for use on lawn diseases from Rhizoctonia.
You probably won't need to adjust the timing on your routine fertilization. We include timing recommendations for zoysia in our Lawn Fertilizer Schedule.
Miri
We consulted with one of our turf experts as this was an uncommon symptom in zoysia. Based on the photo, he believes this is a disease called Large Patch, which is caused by (potentially) different fungi than those responsible for Brown Patch, though they are all in the same genus of Rhizoctonia.
Not all fungicides will suppress these fungi, and the timing of application can be important for good treatment efficacy. Typically this infection begins in autumn, so sprays attempting to cure existing infection may not work (or at least will not work quickly). Preventative applications made in autumn, before symptoms appear, should be more successful, though repeat applications will likely be needed. (You'll have to see what the product label says about timing and intervals.)
Fortunately, this infection tends to leave turf crowns (the origin point of growth) and horizontally-spreading stems intact. Since zoysia is a warm-season grass, it should begin to regrow vigorously once our weather remains warm, and it may be able to self-repair by itself. The fungicide you've already applied might halt some fungal spread among the still-green growth, but the damage has already been done to the brown foliage.
Conditions conducive to infection include any degree of shade and areas that collect extra water (such as from a roof downspout outlet) that don't drain well. Core-aeration this summer might alleviate compaction that is slowing drainage; otherwise, locations in the yard that are not easily altered to improve conditions for the turf should be converted to alternative groundcovers so this disease is not a recurring risk.
Fungicide active ingredients that should provide the best control for Large Patch include azoxystrobin, flutolanil, and tebuconazole. Not all may be available to the general public, but can be applied by pesticide applicators via a lawn-care company. Given the cost of some fungicides and the relatively small volume used per application, the most affordable option may be to hire an applicator. You may need to have applications made around September and again in March, but verify the timing instructions specific to each individual pesticide product; even those sharing the same active ingredient may not have the same application instructions. Similarly, make sure a fungicide that contains one of those active ingredients is labeled for use on lawn diseases from Rhizoctonia.
You probably won't need to adjust the timing on your routine fertilization. We include timing recommendations for zoysia in our Lawn Fertilizer Schedule.
Miri
