Our prairie reconstruction process began in the summer of 2017, after receiving the Comed Green Region Grant, and under the guidance of ecologist Dave Eubanks. Our proposed plan would replace 1.25 acres of sod to native prairie plants, the majority located in a detention area west of our Township Highway Dept. This area receives stormwater runoff from our property in addition to housing a septic field. Sections of this field rarely dried enough to mow with a tractor without getting stuck or leaving ruts. There is a storm drain that does empty some of this field into a drain tile further down the water shed, but our goal is once the prairie plants are established, we will be able to retain all our stormwater onsite.
Slowing the runoff of stormwater encourages more water to be absorbed into the soil, cleaned and used by the plants, but also to recharge groundwater aquifers, rather than sending it downstream, causing flooding and erosion along stream banks and rivers.
The first order of business was determining the boundaries of our proposed area and killing the turf. If you’re anything like me, you’re thinking “How did you do that without using herbicides??” I didn’t. We used Glyphomate 41, which is like glyphosate but is safe for amphibians and other water dwellers. Believe me, if there was any other way, I would have done it. On smaller areas, I use old carpet to smother grass. I’ve also used clear plastic flat on the surface to work as a greenhouse and solarize the plants, killing them. I’ve experimented with organic weed killers, only to have to retreat time and time again. Tilling turns up so many weed seeds that it’s strongly discouraged.
So sadly, for now, herbiciding is the only way to kill large sections to plant for natives. Here’s how I think of it: It’s a one time use. Sure, I will have to spot treat weeds in the future, but this is the only time I should have to spray large areas. Compared to farm fields who use Round-up over and over again, I feel like our impact is minimal and our desired outcome (more native habitat) essential.
Herbiciding must be applied when the plant is actively growing, which tends to preclude mid-summer when grass is often dormant. As soon as it starts growing again (in late August of this particular year), we sprayed Glyphomate 41 on a calm day. Thirty days later, we used a backpack sprayer to target any green growth. By late September, we had a solid pale yellow patch of dead turf.
The next step is burning the dead turf to allow the seeds to make better contact with the soil. We applied and received a permit to burn from the IEPA. Our burn in late October was not exciting at all. The area, though dead, didn’t have enough fuel (dead grass) to burn and areas ground were still wet. We used propane torches rather than drip torches to help it along, but our burn was spotty. We did see more exposed soil, so our work wasn’t completely in vain.
Due to the frequently wet nature of this detention area, our ecologist, Dave Eubanks, chose two seed mixes from Genesis Nursery in Tampico, IL for us. One was a wetland/detention area mix including tough grasses that can tolerate the salt runoff that occurs during the winter. The other mix was a wet mesic prairie mix.
Our seeding event took place on a cold day in November. We shook our seed bags to intersperse the small seeds with the large seeds and filled our 5 gallon buckets half-full with seed.
The seeds in these mixes come in all shapes and sizes, and the small ones tend to fall to the bottom of the bucket. After every couple of handfuls are dispersed, we would re-stir the bottom of the bucket with the top.
In order to create as much competition as possible to provide weed control, we seeded at a higher rate than necessary. We targeted roughly 100 seeds per square foot. Obviously we weren’t counting, but that gave us a good baseline of how to distribute the seeds.
Our site required erosion blanketing. This step is important on slopes and in wet areas since one heavy rainstorm might completely displace the seed before it germinates. In areas that stay wet, we used a coconut coir blanket. The other areas were straw. Both blankets were netted with bionetting that would be less likely to trap wildlife under it and would decompose after 18 months. The blankets were ordered from North American Green.
This step was time consuming and arduous. It was a lot of ground to cover (ha) but we completed the seeding and blanketing of 1.25 acres in a day.
There are benefits to seeding in the fall/winter time. Many seeds require a cold weather stratification process before they will germinate. The seed likes dormant through winter and then knows it can safely germinate in the spring. The heavy weight of the snow also helps the seed make contact with the soil. You can also plant in the spring, which we did at Behm Park in 2019 due to winter starting early the prior November. We will likely see mainly grasses growing in the first year and the forbs will wait until they have experienced a winter before germinating.
The growth you see with native plants this first year isn’t show stopping. Native plants are known and valued for the deep, complex root systems, which take time to grow. The first couple years, expect to see minimal growth above the ground while their energy is churning wildly below. Year three is when we expect to see something that resembles the prairie we are going for, although some species take even longer to grow to maturity.
What you will see the first year are weeds. Lots of annual weeds for us. Wild lettuce, Queen Annes Lace and a number of other unconcerning annuals. During the first year, we planned to do 2-3 mowings. We would let the plants get to knee height and then mow to six inches. This step allows sunlight to reach the developing natives and prevents the weeds from going to seed. We did two mowings and several line trimming to keep annuals from going to seed.
During this first year, we were also keeping our eyes open for biennial weeds that may not be flowering, but will be forming their tale-tell rosette. These rosettes (especially teasel) should be treated with herbicide. Thankfully, we didn’t have teasel. Thistles are another commonly frustrating weed that requires herbiciding. This is best done when they are small, or after they are grown, cut the stems at the base when they are about to flower and then treat with herbicide before fall as they are storing up energy in their roots. They have rhizominous root system that enables the plant to spread underground via roots in addition to seeds.
While we were expecting a weed patch, we were pleasantly surprised at the beauties that did show their smiling faces in the first year. Partridge peas, asters, and black eyed Susans made for a charming short meadow during our first year.
During the second year, we kept our eyes peeled for the big thugs, like reed canary and phragmites that will crowd out the natives, making all our work in vain. The only plant so far in concern in our wet prairie are a few cattails. There is a species of cattails that are native, and cattails are very effective at absorbing excess nutrients like phosphorus, and they can also spread rapidly and create monocultures, which are areas of little to no diversity.