LAWN/GOLF: In what month do you first fertilize zoysiagrass?


Update (03/01/2016)

Getting Itchy...

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Even though the calendar has yet to turn from February, spring has been in the air over the last two weeks in Missouri.  Over the past 30 days, the western portion of the state is nearly 6 degrees above normal, the middle 4 degrees above, and the east is 2-3 degrees above.  Although the final tally isn’t complete, our state climatologist Dr. Pat Guinan estimates we will rank in the top 10 warmest December – February spans, and this winter will be the mildest since 2011-2012.  Going back through the reports, I recall observing brown patch on tall fescue and dollar spot on bentgrass in mid-late March of 2012, as well as a very, very long and severe season for large patch occurrence (Click here to see the 3/29/12 report).  Some have reported quite a few mowings of putting greens already, and the forecast seems to indicate springtime temperatures will hold at least through early March.

Both January and February have had below normal snow/rain fall totals with January being approximately 1” below normal and February being 1.5” below normal in most portions of the state.  The dry January has followed a trend of dry Januaries over the past few decades.  A bad year for those supplementing income from snow removal, but a good year for cities to save money on snow removal services.  On the turf side, I would be worried with the lack of a cozy snow blanket on bermudagrass, but we haven’t had a sustained cold snap of temperatures to draw too much concern.  Newly established areas or north facing slopes may have some winterkill, but most of the extreme temperature dips were accompanied by a little snow cover which should mitigate some of the loss.   

Quick Hits

  • Pink Snow Mold/Microdochium Patch: Pink snow mold damage has been reported on a golf course green near Kansas City.  Although lacking the sustained snow cover of our northern neighbors, pink snow mold is a common occurrence in middle MO on putting greens, and should be dealt with in either a late fall application or hopped on very quickly in a curative situation.  The pink coloration on the patch margins is the sporodochia, or spore producing structure of the pathogen.  When observed, this means thousands more spores are being produced which will facilitate disease spread.  Medallion (fludioxonil) or a tank-mix of 26GT (iprodione) + Daconil Ultrex (chlorothalonil) should be applied on symptomatic areas.  If not, a cool spring rain or irrigation can move spores quickly and cause greater areas of infection.  Areas may be treated with a Spray Hawk or other hand-held boom sprayer to reduce traffic impact across awakening bentgrass.  
  • Missouri Pesticide Collection:  If you have done some pre-spring cleaning and have unused pesticide waste that needs to be disposed of, the Missouri Department of Natural Resources has a informational fact sheet (Click Here to View).  Non-business entities such as farmers and households may take part in the Missouri Pesticide Collection Program.

  • Late 2015 Flooding in St. Louis: In late January, I bore witness to my first St. Louis flooding event, and the awe of Mother Nature’s wrath has never been more apparent.  Greg Parkinson, course superintendent at Tapawingo National Golf Club, gave me a brief tour of the aftermath which included 1.5-2” silt deposits on 17 holes, including greens and tees, and a 7-8 foot deposit of sand on holes along the Meramec river’s edge.  The crew had been working 7-day, 10-12 hour shifts since flood and it showed as all greens were clear by late January, and 7 holes remained with silt. I can’t imagine a worse time for this flooding to occur, as seasonal maintenance crews are at their lowest, winter sunlight is fleeting, and freezing temperatures cause delays.  

    In the picture above, note the irrigation heads running, which boggled me prior to Greg’s explanation that the silt couldn’t be pushed effectively without some moisture.  Many other courses near the Meramec such as the Quarry at Crystal Springs were also affected, and my kudos go out to the crews restoring these properties, and the collaborative STL superintendent community who continue to lend equipment and labor support to aid in the recuperative effort.  During my visit, the maintenance crew from Bellerive Country Club was on site to help, along with Mike Munie and his staff (Perfect Play & Links) shown in the picture above. 

    Where pests are concerned on these flooded sites, there is not much scientific data to draw from on how prevalent they will be after the cleanup.  My inclination is the flood was a huge reset button, and all pesticide applications from the previous fall will have reduced or no effectiveness.  A conflicting view is the pests rolled away with the flood, but many pathogens, at least, overwinter safe and sound in infested plant material or tightly bound thatch, so the diseases should recur just fine in 2016.  At least one spring application for large patch (which our research shows should be in the plan anyway) should be made, and intense monitoring in early spring for Microdochium patch on greens should be conducted.  Additionally, putting in a program for Pythium root rot on these sites in mid spring would be wise, since incidence and severity of this disease increases greatly in a saturated soil situation.
  • Dormant Seeding:  If you have some bare areas and missed that important fall seeding window for cool season turfgrasses, now is a great time to “dormant seed” and put some competitors out to fight the weed seeds this spring.  Both cool-season and warm-season grasses alike can benefit from a late winter seeding, since it allows them to take advantage of the first possible germination environment to begin establishment and mature before the stress and pathogens of summer arrives.  For more information, see our article here


  • Building Update:  The finishing few inside touches are being put on our new office and storage space for the MU Turfgrass Program.  This construction effort, led by Daniel Earlywine and the great crew at South Farms, was funded through donations to our Turfgrass Building Fund.  This smaller building helps us get out of the current “house” which was officially condemned last year due to a sinking foundation and general unsafe conditions.  We hope to start moving in around the beginning of April and get ahead of the upcoming field season, which as noted below is approaching with alarming pace.

Part I: Spring Application Timing: Resources

As the spring, with a kickstart from a mild late winter, approaches, we are all getting itchy to get started.  For me this statement is literal, with allergies already causing issues with itchy eyes and nose, (could be a bad pollen season).  I’ve also had some inquiries, particularly from southern MO, about the need to start early on pesticide applications. It’s not time to scratch that itch yet, but in this Part I of a series I’d like to begin with some of the resources I use to get ready for and time spring pesticide applications.

  1. Sprayer Calibration:  More than likely, you have already done this, but there is some information that may help keep the sprayer properly calibrated throughout the season.  If you are not using the 128 Rule, then I strongly advise that you should.  Using an ounce as a measure (since it’s 128th of a gallon), and the time to cover an area of 128th of an acre (depending on your nozzle spacing & speed), you can use a simple collection cup to calibrate the output in GPS from your spray nozzle.  During the season you can go back, and check each spray nozzle to make sure the output is within an acceptable range.  If not, it may indicate a cloudy screen or need to change the nozzle.  Methodology for the 128 rule can be found here.  On another note, give the sprayer nozzles and screens a once over, and change if they’ve been used for a whole season.  A good rule of thumb for nozzles is to change them when you grind or change the mower blades on a rotary mower.
  2. Daylength:  I keep an eye on daily photoperiod length to get an idea of what a high temperature really means in regards to overall impact on the ecosystem.  A 75 degree day will result in a much higher impact on average daily soil temperature, plant, and pathogen metabolism in May when the photoperiod is 14+ hours long than it will in February when the photoperiod is 11 hours or less.  The Astronomical Applications Department of the US Naval Observatory provides an easy to use form here that can show the annual duration of daylight for any U.S. or worldwide city. A more user friendly interface showing photoperiod by month can also be found here.
  3. Growing Degree Days:  Other than calculating growing degree days yourself by using your daily high and low temperatures in the formula [(high – low)/2] – the base (i.e. 50 or 32), the growing degree day tracker operated by Michigan State University ( gives an excellent overall map of the degree day status and corresponding pest biology for much of the Midwest region.  In addition, you can sign up by zip code to receive pest alerts from the nearest weather station in their network.  If you also use GDDs for PGR scheduling, Dr. Bill Kreuser from U. of Nebraska also has a downloadable Excel spreadsheet embedded with macros to help track PGR usage and GDDs (for more information click here). 
  4. Soil Temperature: Services vary somewhat from state to state, but in Missouri I rely heavily on Horizon Point reports for soil temperature and other weather information.  This free subscription service sends weather reports daily into your email inbox from the nearest reporting weather station to your zip code.   One can tailor the reports to what they need, but at a minimum I recommend the wind forecast to plan future applications and reduce drift potential, the spring planting soil temperature chart which shows a graph of 2” soil temperatures, and the Weed Scouting Aid.

Current Status: Some forsythia got tricked down in Springfield and concerned some, but it’s still a bit too early to use that itchy trigger finger on preventive applications. Although we had a few brief temperature spikes in late January and late February, soil temperatures in the 55 – 60 degree F threshold have not occurred. Remember also that for soilborne disease prevention, soil temperatures are often averaged over a 3 or 5 day span to account for springtime variability.  This need for sustained mild temperatures often leads to an early to mid April time frame in Missouri for fairy ring prevention, but the way this year is going perhaps we will be a week or two earlier.  Remember 2011-2012…             


Lee Miller
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Extension Turfgrass Pathologist
University of Missouri