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 still
Grubs are active. If the extreme heat
keeps up, we'll be seeing the effects of grub damage this month.
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 on trying to apply grub treatments for the Japanese beetle
grub. Carbaryl (Sevin) granules are an option for Japanese
beetle grubs, but they 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, at least to
start the season.
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 a deep thatch layer, these
seeding dates also define ideal times to dethatch or aerate.
Thatch layers should not be over a half-inch deep for optimum
growing conditions. When aerating, make sure you use a core-type
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.
[to top of second column]
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. As many have found out,
a second treatment about June 1 is also necessary since the products
only last six to eight weeks.
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. Dicamba is particularly prone to vapor drifting, for up to
two weeks, with hot, sunny conditions. It's hard to get a good
weather forecast for two weeks, let alone the week we are in.
Another invasive plant, teasel (see picture at top), is easily noticed along highway
and railroad right of way. The plant looks like a thistle and has
gone gangbusters since spray programs have been curtailed due to
budget restrictions. The plant behaves like a biennial in that it
has a small rosette stage the first year, then bolts to the tall,
flowering plant the second year. This life cycle is similar to
another invasive plant: poison hemlock.
The best controls listed are triclopyr and glyphosate (Roundup).
The trichlopyr is a broadleaf-only weed killer and is often used to
help with control of violets. The glyphosate will take out both
broadleaves and grasses, so it is most effectively used by wiping on
a few isolated plants.
University of Illinois Extension, Logan County]