Steps in Prairie Planting
The steps we used in prairie planting are: 1) Preparation
of the field for planting; 2) Collecting seed from suitable
sites; 3) Handplanting, usually in the late fall of the year;
4) Mowing or handweeding for the first year or two after planting;
5) Conducting controlled burns annually, beginning as soon
as there is sufficient fuel to carry a fire; 6) Continued
handweeding until the prairie is well established.
It is important to understand the life cycle of a prairie
plant. Most prairie plants have extremely deep root systems,
and the first year after seed germination, the plant expends
most of its energy in making roots. Research has shown that
mature plants of most prairie species have root systems several
to many feet deep. It is only because of the deep root system
that prairie plants can survive the common droughts of summer.
Thus, the first year after planting, prairie plants may grow
only an inch or two, but develop good root systems. Most of
the greenery that appears the first growing season of a new
prairie is due to weeds, primarily shallow-rooted annual or
biennial weeds that develop from the existing seed bank. It
is only after the second or third growing season that good
prairie plants are visible, and it may take five, six, or
more years for some of the more conservative prairie species,
such as compass plant, lead plant, and shooting star, to become
established. Thus it is important to have patience. Even more
important, it is necessary to discourage the growth of weeds
until the prairie species have become well established. These
principles guide the steps in prairie creation outlined below.
Preparation of the field Fields that remain
fallow in southern Wisconsin usually revert to nonnative species,
both grasses and forbs. The primary grass in our fields was
smooth brome (Bromus inermis), with nonnative forbs
such as Queen Anne's lace (Daucus carota), ox-eye
daisy (Leucanthemum vulgare), wild mustard (Brassica
nigra), and red clover (Trifolium pratense).
Except for a few corners, there was nothing "good"
on these fields. To prepare the field for planting, this nonnative
vegetation was removed by spraying three times with glyphosate,
a nonspecific herbicide. For the first spraying, the herbicide
2,4-D, which is active only against broad-leaved plants, was
also added to the spray mix.
Seed collection Seeds for the planted prairies
were collected from remnants elsewhere on the property, or
from nearby sites. Fortunately, Pleasant Valley Conservancy
had significant populations of two major native prairie grasses,
Indian grass (Sorghastrum nutans) and little blue
stem (Schizachyrium scoparium). We also had good
populations of many prairie forbs. A few desirable forbs not
available in the area were obtained by trade from other prairie
sites in southern Wisconsin. Seeds were cleaned to remove
stems and extraneous matter. Seed collecting procedures are
discussed on another page.
Handplanting Volunteers planted the fields
by hand in mid November. Seeds to be planted were weighed
to ensure adequate densities and then mixed with sawdust to
ensure good distribution. The fields were marked into uniform
small plots and each volunteer was assigned a plot.
| Volunteers relax after planting
the Pocket Prairie. See photos above for "before
and after" shots. |
Mowing As noted, the first year on a planted
prairie is a year of weeds, lots of them. Since the prairie
plants are only an inch or so tall, mowing does not hurt them.
Rather, it keeps the field open so that the prairie plants
receive good sunlight. We hired a local farmer to mow our
planted fields. The mower height was set to about 4 inches,
short enough to cut the weeds, but tall enough so the prairie
plants are not cut. The timing of mowing depended upon the
prairie, the weather, and the kinds of weed species in the
seed bank. Mowing two or three times the first growing season
was always required. In some cases, we had to mow part or
all of the "prairie" during the second year. For
two prairies, the whole field did not need to be mowed, but
only those areas where undesirable weeds were most prevalent.
Handweeding Once mowing is discontinued,
weed control must be done by hand. (Use of herbicides is not
advisable, because it will eliminate desirable species as
well.) Handweeding is one of those chores of prairie restoration
that seems to go on forever, and in fact, this is the case.
Even if the field was completely free of weeds at the start,
there will still be a weed problem. Some pesky weeds we had
were: sweet clover (Melilotis alba), wild parsnip
(Pastinaca sativa), Queen Anne's lace (Daucus
carota), and mullein (Verbascum thapsis). Fortunately,
all of these are biennials, and could be pulled relatively
easily in their second year of growth. It is important that
they be pulled at the time of flowering, but before seed set.
If we had to pull them when they were setting seed, then we
bagged the plants removed them from the field.
Controlled burns By the third growing season,
prairie grasses should be established sufficiently so that
controlled burns are possible. Controlled burns are vital.
They discourage exotic plants and encourage the growth of
prairie plants. Early spring burns are best, and they should
be continued annually for five or six years. Once the prairie
is well established, burn frequency can probably be reduced
to once every two to three years, although it usually does
not hurt to burn a planted prairie annually indefinitely.
We have continued burning our planted prairies even after
they had become well established. Burning stimulates growth
of prairie plants, and greatly promotes production of viable
seed. We used the seed produced by the first-planted prairies
for the later-planted ones.
|
| Contrast between burned (right) and unburned (left) parts of a planted prairie. The grass is primarily Indian grass. The burn was done the previous year. Toby's Prairie in late winter 2007. |
Monitoring A planted prairie should be monitored
carefully to determine what species are present, and to detect
new species when they first appear. Some species may not show
up for six or more years. Monitoring is also essential to
catch weed problems. Once a prairie has been well established,
it now becomes a source of seed collection for planting other
fields. This process can go on indefinitely.
Skill is needed to recognize prairie plants during their
first year or two. Unfortunately, the only way to obtain this
skill is by learning from experts. For this reason, we recommend
attending frequent field trips and participating in volunteer
workday activities.
One of the principles of prairie restoration is that the
perennial prairie plants will eventually outcompete the weeds.
In a tall-grass prairie, the native species create prairie
sod, which keeps weed seeds from growing. Also, the tall grasses
shade out the weed species, inhibiting their growth. Careful
monitoring will provide useful insights into this competitive
situation. |
