I received a question the other day about summer patch in Kentucky bluegrass. I had been thinking about summer patch that morning and was planning to write about it this week. Normally, early May is when that particular disease is on my radar but since everything is early, the time to think about it is now.
The symptoms tend to show up when summer heat and drought fire up, but the infection occurs in mid/late spring. The fungus is soilborne and attacks roots. If you have a site with a history of this disease, fungicides may be helpful. When the daily max soil temperatures at 2-3 inches deep are consistently (3 days in a row) above 65, that’s a good time to make a first application. Follow up 28 days later, or according to label intervals.
You can get some soil temperature data info at the Kansas Weather Data Library:
At the upper left, you can choose “Kansas Weather and ET Data” and from there you’ll find a page with a map and also a pull-down menu. Choose a site near you, select a range of dates, and you can get highs, lows, and soil temps usually at 2 and/or 4-inch depths. Or, better yet, invest in some of your own soil temperature equipment.
There is more information about summer patch at the summer patch link HERE