February 2017: Anything but Normal
At what point does the data depart from normal that it becomes more than “extra” ordinary? The previous meteorological winter, or lack of it, has riled the bushes (forsythia) and many plants (daffodils) to bloom in February rather than late March or April. February 2017 ranks as the warmest of all time, at an astounding 11.5 degrees above normal. This follows a 2017 January that was 5 degrees above normal. Together they equaled the warmest combined Jan – Feb of all time, and even with a slightly cooler than normal December elevated the 2017 Dec – Feb winter season to the 4th warmest all time. For the record, “all time” is compared to weather data on record from 1895 – 2017, or the previous span of 122 years.
Snowfall and precipitation have also been well below average over the previous 5-month span in Missouri, resulting in the region being placed in a moderate drought designation (http://droughtmonitor.unl.edu). February precipitation totals were 1 – 2” below normal throughout the state and into western Kansas and northern Arkansas. In addition, winter snow only accumulated to 1.5 - 2 inches through much of the state, leaving very little melt to satisfy soils. Irrigation systems, particularly on golf courses, needed to be fired up earlier than most can remember, and golf greens without water (see below) are showing considerable drought and even fairy ring symptoms. In case you didn’t see the headline (http://wgntv.com/snowcover), Chicago had no snow cover (defined as a 1 inch accumulation) in January or February for the first time in 133 years of recorded weather. Incredible times we are living in.
Although March started out chilly, the warm weather looks to return consistently over the next 14-day period, starting with this weekend’s return to the middle and upper 60s. For flowering, frost sensitive ornamentals (and frightened fruit trees), what does this mean from a historical perspective? Last year, Dr. Pat Guinan created a valuable online resource in the Missouri Frost Freeze Probabilities Guide, that is an extensive review of the likelihood of various low temperatures (36 F, 32 F, 28 F, 24 F) in spring and fall based on 1981-2010 weather data. The spring median date of a low temperature equal to or below 24 F is late March for most weather stations in Missouri (click here to view), which means there is a 50% likelihood the 24 F threshold will occur after that date. Last year, 24 F did not occur past late March, but several lighter frost events occurred after our forsythia bloom (just like they have in the last couple of days).
8-14 Day Outlook: Continued Wave of Warmth
Dealing with Pests Without the Old Man
Looking back on both the above graph and last year’s first report, we are seeing a two-year trend of an extended growing season with warmer than normal fall and spring periods. This year, however, combines that aspect with a considerable lack of weather from Old Man Winter. While the advantages are a boon for revenue (more mowing, more rounds) and a longer window for cool season turfgrass growth/potential seeding, what might this mean for battling turfgrass pest issues? For many, the requirement may be a bit extra.
*Click on the link here for the first spring 2016 report that has additional tidbits on daylength and sprayer calibration.
Just a quick glance at the growing degree day (GDD) tracker (http://www.gddtracker.net) demonstrates the story quite nicely. While last year was historically also a warm winter, approximately 130 more base 32 GDDs and 40 - 60 more base 50 GDDs have accumulated in 2017 than at this point in 2016. This is an extraordinary amount, considering the comparison is not to an average winter, but to the 5th warmest winter on record. Two-inch soil temperatures were also exceptionally high in mid-February, breaking into the 55F threshold before dropping back down in late February. Another late warmup flash in the last few days caused them to spike again before dropping this week.
Spring Soil Temperatures Teeter with February Swings
Dealing with Pests Without the Old Man
Winter annuals, particularly henbit, are flowering like crazy, and even a dandelion or two is getting spunky in some areas. I have not observed any crabgrass germination yet, but www.gddtracker.net has the region in the early optimum range for preemergents and we have reached the 55F soil temperature mark. I have heard some reports that preemergents on some lawns in St. Louis were applied in mid to late February. Expect 6-8 weeks out of a preemergent application, and August is a long way away. If applications have been made or are planned soon, the schedule should be for at least a split application and perhaps even a third application in May. In years similar to this (2012 and last year), crabgrass broke through in early August on lawns with applications ending too early in a broadened spring. If applications are planned later this month around a “normal” window on lawns, consider using dithiopyr or other herbicide with some reach back activity on young seedlings.
For Poa annua seedhead management on golf greens, the window for the first application is open (again as shown on www.gddtracker.net) and will continue to move along with the forecasted warm temperatures. Make these applications soon, as several throughout the region have observed the problematic weed in the “boot” stage.
For the most part, the endemic bugs that overwinter here will be active earlier, and the migrating moths bearing turfgrass loving larvae will also probably arrive here earlier. Expect cutworms and other migrating moth larvae pests earlier than normal this year, and scout greens accordingly for them. No moth flights have been reported yet, but honestly few traps are out this early in the season. Several have noted billbug adults roaming around, but peak activity should be a few weeks from now, as will be the timing for a preventive application on historically infested zoysiagrass sites. Earthworms have been actively mounding over the past few weeks, as are the moles destructively tunneling around to feed on them.
Drought shows fairy ring
Dry weather and no irrigation will uncloak fairy ring symptoms from below. - Feb. 27th
Good news/bad news here. As you can see above, drought symptoms on putting greens can show some early Type II fairy ring activity. As stated previously, most golf courses have fired up the irrigation, mowed a few times, and are in full swing so these symptoms probably aren’t prevalent (but the little monsters are present). The temperatures aren’t quite there yet for preventive spring DMI applications, so hold the line. Remember the timing for the first application is based on (1) the 2” soil temperature buffered on a 5-day average, and (2) a threshold range of 55-60F is required for a few days, not when soil temperatures tickle 55F and fall away as in mid-February. This being stated, if the threshold is reached in March instead of April, I will recommend the preventive application. It may also be wise, however, to have a third application in the hopper if the 2nd application 28 days later doesn’t make it to May. Hard to make it to August from April.
On the research farm, we are planning our “early” fungicide application for large patch control next week as we will most certainly eclipse the 50F soil temperature threshold again. Last year, the early application was made on March 11 and again this year the application will be made to post-it yellow zoysia. Way too early was my previous thought, but, (as I’ve been talking about all winter long), the early application made on March 11 was considerably more effective than an application made on a 60F soil temperature threshold a month later on April 22. As for good news, the current dry conditions should mitigate large patch infection, at least for now. Spring is the time for large patch control, however, particularly if you only get one shot at it per year.
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Extension Turfgrass Pathologist
University of Missouri