Winter Weather Warnings
Weather:
An unusually mild and wet winter weather pattern
has settled in over most of Illinois since early November. Temperatures
are averaging 8 to 10 degrees above normal for the first 10
days of January in the Chicago area, and we have received around
2 inches of precipitation since New Years Day, which has fallen
as snow, sleet, or rain from north to south. Temperatures and
precipitation are more extreme in central Illinois. For example,
the average temperature in Peoria is approximately 12 degrees
warmer than normal, and almost 3 inches of rain has fallen in
January (normal ppt for January is 1.5"). Based on heavy
rains along the southern California coast, and heavy snow in
the mountains, it seems like a nasty El Nino pattern has set
in. However, meteorologists are downplaying that angel for now.
Global warming theories, anybody???
Although this weather pattern has been pretty
good for human inhabitants who hate cold and snow, it may be
setting us up for a major winter injury/winterkill problem on
our turfgrasses and ornamentals -especially if a sudden cold
snap occurs that rapidly drops air and soil temperatures to
near zero F. The most susceptible plants to this type of injury
seem to be Poa annua, perennial ryegrass, and hybrid rose bushes
(!), but other turfgrasses and ornamentals could be injured.
The current forecast is for more mild and wet conditions through
tomorrow (Wednesday, Jan 12), followed by a huge cold front
that will drop temperatures well below normal by Thursday night.
(see graphic below) Low temperatures in the single digits
are expected for several days. An unpleasant scenario for both
people and plants!
A major cause of winter turf loss is a condition
called "crown hydration-freezing injury." Many turf
swards are now saturated with water or covered with melting
ice and snow, and there is a chance that Poa and other plants
have warmed enough over the past two weeks to break dormancy
and soak up some of this water into the roots and crown area
("crown hydration!"). Sudden freezing of the water
in hydrated tissues causes ice crystals to form, which will
damage the cell walls and membranes of individual cells to the
point that entire tissues and plant organs will fail. Unfortunately,
this type of injury often goes unnoticed until spring green-up,
when large areas of turf fail to green up and begin growth in
early spring. Again, Poa annua is the major victim for this
type of injury, but other plants may also be affected.
But wait, there's more! Layers of slushy ice and
snow still cover many turf areas in northern Illinois. Tomorrow's
warm rain may not melt the slush layer entirely away before
the deep freeze, so a frozen ice/snow layer may form over the
turf in poorly drained or shaded areas. Long term coverage by
ice layers is another cause of winter injury - again primarily
to Poa annua. In this case, the injury is caused by anoxia (lack
of oxygen) and accumulation of carbon dioxide when
the turf lies dormant for long periods under ice sheets. It
turns out that even dormant plants lying under snow and ice
need small amounts of oxygen to survive the winter. However,
it takes 30 days or more of solid ice cover to damage or kill
a Poa annua turf, and 45-50 or more days to hurt creeping bentgrass.
If our warmer than normal pattern continues, hopefully any snow/ice
sheets that form will melt before 30 + days have passed… STAY
TUNED!
+++++++++++++++++++++++
Thanks for your support of this, as well as all
of our research programs,
Randy
Kane
CDGA
Director of Turfgrass Programs
Midwest Golf House
11855 Archer Ave
Lemont, IL 60439
630-257-8126
Lee
Miller
CDGA
Manager of Turfgrass Research
Midwest Golf House
11855 Archer Ave
Lemont, IL 60439
630-257-2005 x.106
