Crabgrass has done very well this summer
Glenn Hardebeck, Turfgrass Research Agronomist, Department
of Agronomy, Purdue University
Timely rains have not only helped keep Kentucky bluegrass
lawns green across most of Indiana this summer but it has also
produced a significant, fast growing crabgrass problem. Early rains
through June and into July promoted crabgrass germination while
continued rains through August have encouraged growth to the point
that many homeowners are having difficulty with clippings. Normally,
clippings are not a significant concern on unirrigated lawns during
the summer, but good soil moisture and moderate temps have produced
an unusual flush of growth for lawns that are usually dormant at
this time. Add to that, an infestation of fast growing crabgrass
and you end up with a hay producing lawn.
crabgrass can be controlled post-emergently, control at this late
stage would be sporadic requiring at least two applications of
something such as Drive (quinclorac). And, since crabgrass will
begin to die once we wake up to a frosty morning, crabgrass controls
are not recommended at this time. As with any thin lawn, concentrate
on good fall fertility to increase the desirable turf’s density.
Clippings are only an agronomic problem it they are smothering
the turf below. Remove clippings only if necessary and try to increase
mowing frequency to avoid clipping problems if possible.
Click image to enlarge
Pic 1: Crabgrass has had a good year to germinate and grow.
Pic 2: July and August rains have encouraged a growth flush unusual
for many unirrigated lawns with crabgrass adding to the clipping