Dear Expert, my St Augustine grass has developed "yellowish" spots/patterns. I've applied fungicide which has not helped. Please see enclo...
Knowledgebase
Lawn spots #753539
Asked June 02, 2021, 2:09 PM EDT
Dear Expert, my St Augustine grass has developed "yellowish" spots/patterns. I've applied fungicide which has not helped. Please see enclosed pictures. Can you tell me what's causing this and how I can treat it?
Thank you in advance
Montgomery CountyTexas
Expert Response
Thanks for the submission. Let me start out with the most important message. Fungicides are not curative... they are better as a preventative and will help reduce the spread of a fungus. Now... as for the issue. Has this happened before? Are the areas low spots? or hold more moisture? When did you fertilize your lawn?
Hi. Yes this happened a year ago, and no, they are not in low spots. I last fertilized with “Scott’s Weed & Feed” in Late February.
> On Jun 3, 2021, at 9:14 AM, Ask Extension <askextension> wrote:
>
> fertilize your lawn?
>
> Thanks in advance.</askextension>
Given the conditions and the amount of stress this year, we recommended not treating with fertilizer or weed control products. Weed and Feed products are not well suited for out area. I attached the calendar to provide explanation and a guide to help you in the future. The timing for fertilization and even for pre-emergent control are very different. Fertilization should be done when the lawn is actively growing. (typically April 15th - May 15th) Pre emergent is applied in late January- early February. Why am I mentioning this? This year the stress from the freeze alone weakened the turf. In addition, pre-emergent products and fertilization can contribute to stress. Thus weakening the lawn and making it more susceptible to fungal issues. It appears to be Take-All Root Rot. I am attaching a research publication for additional info. You will need to use the sphagnum peat moss treatment to assist in knocking back the problem. This should be applied now... 1/8" ( basically a fine dusting) and then again in mid July and then another application in early September. Then next year, in late April, make another application and watch for symptoms. Then we can revisit the issue and address additional problems. Let me know if you have additional questions. MP
Thank you, this was very instructional. Where can I purchase the sphagnum peat? And should I apply to entire lawn or just the affected areas?
> On Jun 3, 2021, at 1:09 PM, Ask Extension <askextension> wrote:
>
> sphagnum peat</askextension>
Dear A&M, why do I keep getting this condition on my lawn EVERY YEAR, and always on the same spots? I have followed your schedule of fertilizer, insecticide, and fungicide, along with routine irrigation, and they always come back. What do I need to do? Please help.
Thank you
Juan Cano
Montgomery, TX
<personal data hidden>
From: Ask Extension <<personal data hidden>> Sent: Monday, August 30, 2021 8:54 AM To: Juan Cano <<personal data hidden>> Subject: Re: Lawn spots (#0023470)
Good Morning. Sorry for the late response. The system you submitted to has been down for quite some time. Please let me know if you need assistance still? MP
Hi, yes , I have a lawn issue I could use help with. These large brown areas appear every single year at approx the same spots. I have followed the A&M’s recommended schedule for watering, fertilizing, fungicide, and insecticide, and yet, these spots reappear almost on schedule. What is causing this? How can I prevent it? Please help!
With this drought, watering has been the main issue. There are several things it could be....Have you checked for chinch bugs? In the distance... close to the driveway in your picture, it makes me think it could be chinch bugs. In the closer frame, it appears to be more of an watering issue. Even though turfgrass only needs 1" of water a week, in drought situations, you may have to apply more in order to meet the evaporation requirements. Meaning, if we have evaporation that occurs at 1" for the week, we have to apply 2" to make up for the 1" we lose. Also, double check your irrigation. The heads that spray that area may be blocked by the grass or they may not be covering efficiently. MP
