It's gettin' hot in herre ....

Too dry? Too wet? Both can be trouble!
With temperatures hitting the 90s and 100s in many parts of California, summer stress & water management on greens are becoming more and more of an issue. As soil temperatures start to get into the 70s, cool season turfgrass – like creeping bentgrass and annual bluegrass - starts to slow or even shut down physiologically.

(Photo by Bob Vaughey, GCS, TPC Valencia)

Hot dry conditions can damage plants by pushing them past the point of permanent wilt, killing plants in the process. On the other hand, water saturated soils can lead to anaerobic conditions in the rootzone and superheating of the top layer of soil, effectively cooking plants on greens.

A key to summer heat management is the judicious management of irrigation. Creeping bentgrass can tolerate wilt and drought stress to a higher degree than annual bluegrass, while annual bluegrass still requires light frequent irrigation to compensate for the shallow root systems.

An important part of managing both turf species is syringing with light amounts of water during the hottest parts of the day. A light misting on plants during the day can drop canopy temperatures several degrees. On very hot, dry days, syringing can be performed a few times a day between play to maintain canopy temperatures at an acceptable level. However, if you overwater these areas (which is easy when irrigation technicians are aggressively trying to manage hot spots) – you can end up oversaturating the soil profile with water and scalding the plants.

A Shout out for Fairy Ring
Fairy ring and the development of localized dry spots can further complicate water and plant management on turf. Professor Mike Fidanza (Penn State University), one of the nation's experts on fairy ring, will be presenting a short web seminar on fairy ring this next Tuesday, July 21 from 1:00 – 1:40 PM EST (that's 10:00 – 10:40 AM for us West Coasters). Check out this link for more information: https://www2.gotomeeting.com/register/512391482

What Else is Going On?
Here in California, summer patch and anthracnose on annual bluegrass are starting to roll into the diagnostic lab at a higher frequency. No great surprise given the high tempertures we're having in many parts of the state. Southern blight is firing on a few locations in southern California, and Pythium is active in the Central Valley as night time temperatures are staying above 68F at night.

All I can say is batten down the hatches, because we're a long way away from the Fall and the summer disease season is only getting started here.

Signing off from the Left Coast until next week!

P.S. - I couldn't think of anything scatalogical for this week's update. Megan, the door's wide open for your Friday update if you so desire.