Keep mowing when the grass or weeds dictate mowing. The rule of
thumb is to remove no more than a third of the leaf blade at any
one time. This means that if your desired mowing height is 2
inches, you should be mowing when the grass gets 3 inches tall.
No summer slump this year, due to all the rain. It figures that
we mow every three days all summer long when gas is hovering
around the $4 mark.
I have had some grub samples brought into
the office this week. This means that the grubs are active. Grub
problems are normally found first along walks, driveways or
patios. The insecticide must get to where the grubs are, so make
sure to water the liquid formulations in as soon as they are
applied. The two widely available products are GrubX (halofenozide)
and Merit (imidacloprid). Remember, the active grubs now are
from the June bug, and we'll want to wait another two to three
weeks before trying to apply grub treatments for the Japanese
beetle grub. Carbaryl (Sevin) granules are an option for
Japanese beetle grubs but don't work on the other species.
Yellow grass tops are visible in many areas. This tends to
happen in very wet years when nitrogen is taken from the root
area, and trees and shrubs grab available nutrients. In the
past, treatments haven't had much effect in the current growing
season. Next year you won't see the same problem.
Fall seeding of grass should be done between Aug. 15 and
Sept. 10. This is a tried-and-true date, but the end of the
world won't come about if you are a week later. The goal is to
give the seed enough time to germinate and become established
before bad weather arrives. Seed at the rate of 4 pounds of seed
per 1,000 square feet on bare spots, or half that rate on
If you have a compacted yard or have a deep thatch layer,
these seeding dates also define ideal times to dethatch or
aerate. Thatch layers should not be over one-half inch deep for
optimum growing conditions. When aerating, make sure you use a
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Fall fertilization is also a good practice. If you haven't
fertilized in the last month, consider applying a fertilizer
treatment around Sept. 1. Use about 8 pounds of 13-13-13 fertilizer
per 1,000 square feet of lawn. Try to avoid the high nitrogen
fertilizers this late in the year. It's hard enough to keep up with
the mowing as it is, and nitrogen promotes top growth. The
even-analysis fertilizers will also promote root growth, which is
what we want, going into the late fall and winter.
Crabgrass and other annual grass weeds can be seen about
everywhere. They will die with the first frost, so treatment is not
available or recommended in the fall. Make a note of where these
grasses are, and an overseeding to thicken up the grasses you want
there may help crowd out the annuals. Preventive treatments may also
be applied in the spring (around April 1, depending on soil
temperatures) to kill the germinating seeds.
Last, but not least, is broadleaf weed control. Fall is a
particularly good time to treat problem perennial weeds since they
are sending food down to the roots to overwinter. A spray about the
third or fourth week of September (making sure to use the
appropriate product) can do a world of good on the perennial weeds.
Remember to be very careful with herbicides around perennial plants
since they are also getting ready to overwinter. Also, waiting this
late in the season reduces drift potential for the neighbor's
garden. With hot, sunny conditions, dicamba is particularly prone to
vapor drifting for up to two weeks. It's hard to get a good weather
forecast for the week we are in, let alone for two weeks.
University of Illinois Extension, Logan County]