Frying Pan to Freezer
March came and went somehow very slowly, and quickly at the same time. Temperatures for most in the region were 3-5+ degrees above normal, sending spring plant growth into a quick flurry. Forsythias, daffodil, and redbud blooms bursted quickly, our obvious phenological signs to get the preemergents out. Now in early April, growing degree days are well ahead of schedule with base 32 and 50 GDDs ahead of a much cooler 2019 spring by 227 and 77, respectively as of April 7 (thank you to the gddtracker.net service for this great info). As shown in the above graph, early April has followed suit thus far, with yesterday in Columbia, MO at 88 F. This breaks the record high for the date by two degrees, along with several other cities in mid MO. This trend, however, is set to change…
The big weather story over the next week will be the abrupt and severe cold snap set to hit the region. A 50+ degree change is expected over a 24-hour period (!), and most will have freezing temperatures tonight in a cold snap expected to last well into mid-April. Missouri state climatologist Patrick Guinan termed the forecast "impressive long-term cold with high confidence", and in the last 10 years of writing these updates that dark a shade of blue on the NOAA forecast graphic has rarely if ever graced the screen.
Expect spring to therefore come to a screeching halt, which for us in the short grass growing business may be a good thing during these times. Application windows for preventive herbicide and fungicide applications should extend significantly into the later part of April. Crabgrass seedlings may get burned off. Dollar spot, fairy ring, and other fungal diseases will get muted somewhat after the recent temperature spike to bolt overwintering pathogen populations.
"What about warm-season grasses that have broke dormancy?" In some areas, they may hunker down and retreat back into a dormant state. At this point though, forecasted temperatures alone should not be low enough (low 20s and teens normally needed) to create a large-scale winterkill event, unless on sites that are also chronically wet and shaded (see last year). Taller plants may have a problem, however. Some farmers have planted corn, and the seed is subject to structural damage and death from imbibing cold water. Fruit growers, particularly grape, apple, and peach that are in various stages of bloom due to the warm weather, could also face an extreme loss of yield in this hazardous cold weather shift. Homeowners and gardeners should get used to covering plants.
March also continued the persistent precipitation pattern, with the state over 2.5"+ above normal for the month, accounting for the 7th wettest March on record. This trend dates back well into last year, with 11 of the last 14 months having above normal precipitation. This has sparked a significant flood risk again for the Missouri and Mississippi river basin. After a significant potential rainfall event over this Easter weekend, drier conditions are expected to continue into mid- April, which would be fortunate if the pattern persists.
Wet Pattern Continues
Zoysia Greening/Large Patch Outbreaks Looming
Dollar Spot Early Activity at Turf Farm Hot Spot
Staying at Home, Watching the Grass Grow
From my standpoint of staying home and hunkering down in my oft cold basement, there are some silver linings. Spending more time with family, (perhaps sometimes too much for their liking), adaptation to different and sometimes uncomfortable methods of working, and more time for introspection on the path of my program, and turfgrass science as a whole, are forced changes that in the long run I believe will be of benefit… character builders if you will. Many in the turfgrass industry are considered essential and working, but these, inconvenient at best, forced changes are impacting us all.
The whir of the lawn mower is heard much more often in my neighborhood than ever before. The pronounced lawn mower engine is a constant companion in my home office. Whether from boredom or the excitement of social distancing and exercising, lawns may be being viewed in the same context as gardens and certainly are being mowed more frequently. This concept is in line with the current spike in sales and lack of supply for gardening materials. Increasing the frequency of cut reduces the potential for scalping and promotes canopy uniformity, and therefore is a common theme of beneficial cultural practices for home lawns. This is a point I try to drive home in extension talks to homeowners, so perhaps this is a brilliant flash of silver…
On the flip side, the family walks around the neighborhood demonstrate the desire for low mowing heights has not changed. The sight of bare soil between sparse, scalped chlorotic leaves is common, along with piles of clippings as shown above. A friend commented that his grass was green, growing and too dense after his fertilizer application and he was taking the height down to reduce the density and perhaps more importantly not have to mow as often. We all know this mindset is exactly the opposite of what needs to be done, as taller tall fescue and Kentucky bluegrass will result in less weed competition and a more extensive root system for the travails of summer.
For lawn care operations, sustainable plant health should be an obvious selling point to a consumer determined to have their lawn look like the fairways at Augusta that I now miss seeing so much. For a homeowner that desires a reduction in synthetic pesticide use or wants an "organic" lawn, a high mowing height for tall fescue or Kentucky bluegrass is required practice. Zoysia can be mowed lower, but it also must be done frequently.
For sports turf and golf course management, also seriously consider mowing height at this time when perhaps resources will be limited later. Will going up 0.25 – 0.5" on sports fields or 0.01 – 0.02" on putting greens earlier this spring increase plant health and allow for continued, and perhaps, necessary reduction of inputs later in a difficult season? The lawn model demonstrates doing so now most likely will, and every text book points to raising mowing heights as a practice to reduce disease and stress, which we all could use now.