Three common methods-mowing, burning, and tilling-exist
for maintaining and enhancing grasslands for wildlife. Sometimes
grazing can also be used. Each method can be used independently,
or they may be used in combination. In addition, your grassland
needs to be protected from other disturbances, and the standards
for plant-species diversity, successional stage, and structural
components need to be met. All of these considerations together
form a practice. By heeding the collective importance of all criteria
in a practice when managing your grassland, you can be assured that
you're providing suitable habitat for wildlife.
Remember, complete lack of disturbance is not a
healthy alternative for our state's grasslands. At least one of
these practices should be used for every existing grassland, depending
on the type of grassland, the management objective, and the landowner's
With all three practices, the most important factors
affecting the disturbance's impact on wildlife are timing and amount.
These are discussed in detail for each practice.
Grassland Protection with Delayed Mowing
Mowing at the appropriate times can control invasion
of woody plants in Grasslands but mowing favors perennial grasses.
Forbs, legumes, and annual broadleafs, which all produce abundant
seeds for wildlife, will decrease. Grass litter also accumulates
with mowing. Mowing can be useful, but if possible it is best done
in combination with burning and light tillage.
Avoid mowing any stand of grass between April 1
and August 1, the prime nesting season for most grassland birds.
With cool-season grasses, mowing should also not be done between
September 15 and February 15 to assure that adequate winter cover
remains. If mowing is used instead of burning for managing warm-season
grasses, it should be done only in early spring, from February 15
The exception to these rules is when you are establishing
grassy cover, when you may have to mow to control undesirable weeds.
Then mow as needed with a rotary mower, although generally not after
June in native warm-season grass plantings.
Don't mow more than a third of an established stand
in any one year. This will provide some undisturbed habitat for
wildlife and create a mosaic of different plant heights and densities.
Divide the grassland stand into units, and rotate your mowing accordingly.
For example, if you have thirty acres, you could divide it into
three ten acre management units, mowing each unit once every three
Grassland Protection with Prescribed Burning
Fire can be useful for managing cool-season grasslands
and is the preferred tool for managing warm-season grasses. However,
defining the specific objective for burning and planning before
the burn season are both essential to a successful and safe burn.
A primary benefit of burning is preventing litter build-up (thatch)
in grassy cover. With warm-season cover this helps warm up and dry
out the soil faster in the spring and allows the prairie species
a longer growing season. These factors are important when you are
trying to eliminate competing cool-season invaders that don't thrive
in warm, dry conditions. In all types of grassy cover, reducing
the thatch level also reduces matting and keeps growing plants more
erect. Thinned-out vegetation makes it easier for smaller wildlife
species to travel within the cover.
Frequent early-spring burning (March 15 to April
15) can help control woody plants. Burning at the end of this period
can also help control and eliminate cool-season problem plants in
warm-season grass plantings. But it will also favor the grasses
and cause forbs, legumes, and annuals to decrease. Late-winter burning
(January 15 to March 15) will benefit diversity in the plant stand,
favoring forbs, legumes, cool-season grasses, and annuals, but it
will not be as effective in controlling woody plants, except cedar
and pine. Hand removal or herbicide treatment may be needed to control
woody plants where spring burns are not desired.
Fall burns may be conducted in prairie stands and
may be desired on sites that are usually too wet to burn in the
spring. Burns done in October or early November can help control
or reduce invasion of woody plants and favor forbs. However, fall
burning eliminates valuable winter wildlife cover. It is also not
recommended on newly established plantings located on steep slopes.
Until the grassland has had time to develop its extensive root system,
the site could be prone to erosion if a fall burn is conducted.
As with mowing, never burn more than a third of
the established grassland acreage in anyone year. This rule is especially
important with burning because of the insects that overwinter in
See the "Suggested Reading" resources at the end
of this chapter for information on safely conducting prescribed
Grassland Protection with Tillage
Tillage can be used to thin a grassland that has
become too thick or to establish or promote broadleaf plant diversity
in a grass stand. Light tillage (less than 25% of the tilled plot)
prevents litter build-up and increases legumes and annual plants.
Light tillage may not prevent woody plant invasion. Hand removal,
herbicide treatment, delayed mowing, or prescribed burning may be
used when woody plants need control. Heavy tillage (more than 90%
of the tilled plot) controls woody plant invasion, creates bare
soil areas, and will convert most cool- and warm-season grassy covers
to old field cover. Any amount of tillage may open prairie stands
to invasion by weeds and is not a preferred disturbance practice
in prairies that already have a high plant diversity. For seedings
that are only grass, however, tillage may improve plant diversity.
As with mowing and burning, never till more than a third of the
established grassland acreage in anyone year, and do not initiate
tillage in new areas during the nesting season, between April 1
and August 1. Fall tillage is often recommended.
Grassland Protection with Light Grazing
Light grazing may be a compatible disturbance with
wildlife cover, but the qualifier "light" cannot be overemphasized.
Bison and elk historically grazed on Illinois' prairie Grasslands
but the grazing patterns were very random and infrequent at most
locations. If you plan to graze a grassland, it should preferably
be done outside of the nesting season (April 1 to August 1). However,
very light grazing during the nesting season may be done without
serious consequences to nesting wildlife. Plant heights of at least
twelve inches should be maintained at all times on grazed grasslands.
Chapter 6 has recommendations for grassland used primarily for hay
It's hard to drive by Dennis Frey's Hamilton County
farm near Belle Prairie City without taking note. The ninety acres
of tall grass-big bluestem and Indian grass-surrounding the family's
homesite provide an oasis in the agricultural landscape. Though
Dennis is a grain farmer, an early job with the soil conservation
service piqued his interest in stewardship. When the district conservationist
wanted to establish a prairie in the county, Dennis was on the committee.
Their discussions came to mind when it was time to put acreage of
his own into the Conservation Reserve Program.
While it appears the grassland was always here,
it happened only with a lot of hard work. According to Dennis, the
most rewarding part was his first good stand of prairie grass, which
didn't appear until three years after he started planting. Dennis
began small, putting in only five acres in the first year, and he
had to master a different kind of farming. He learned that the prairie
grasses needed a fine seed bed, and that after the seed is planted,
it should be rolled. Picking the proper date to plant was also important-planting
the first or second week in June led to 80% success rate.
From that first five acres the grassland on the
Frey farm has grown to over ninety acres. As Dennis continued to
plant; he interspersed wildlife food plots into the area, and even
integrated a wetland. The wet areas became a "field of dreams" for
waterfowl, attracting geese, teal, and mallards.
Once established, the grasses have been fairly
easy to maintain. Different parcels are burned every year, with
the whole cycle completed every four years. "When it burns, what
an awesome sight," says Dennis. "The flames are twenty to thirty
feet high and it sounds like a train. I can't imagine a thousand
acres burning with the wind blowing. What would you do?"
Asked if he would plant his grassland again, Dennis
gives a resounding yes! " While I was always interested in wildlife
as a kid," he says, "these plantings have given me a greater appreciation
of nature. Six coveys of Bobwhite live on the property, and the
grassland provides an escape for deer as they bound across the lane
to disappear into the grass. Red fox can be seen on the hills, and
I even have a beaver dam. Just seeing the wildlife and being able
to watch the ducks and birds close-up gives me a great feeling.
I also find myself spending more time providing for and watching
wildlife than I do hunting."
If he could do it over again, Dennis would plant
more prairie forbs and start earlier, but overall he is happy. This
is the family property where his father was born and farmed. Now
it is Dennis's turn to work their special ground. By his incorporation
of a native landscape into a traditional grain farm, Dennis has
created a treasured place.