Forb Profusion

The reconstruction of Lily's Prairie has been an interesting experiment for us over the years.  When we began to focus energy on converting the old hayfield into a dry-mesic prairie back in 2008, we decided to try and introduce native prairie forbs into the existing grass matrix without the ruthless use of herbicides.  However, after four years of burning and overseeding the old hayfield with native species, it was apparent that the Smooth Brome (Bromus inermis) monoculture was unwilling to cede its dominance to the native species we were stewarding for.  Three years ago, we began to employ a strategy of late-spring annual burning to reduce to the vigor of the cool-season, early growing Bromus inermis.  The strategy appeared to be working to some degree, because the fires would top-kill the early growing grass, which had already spent a large amount of energy growing up to that point.  The early fires would also allow sunlight to hit the surface of the ground which helped to stimulate the growth and germination of native prairie forbs throughout the prairie.

Late spring burns from previous years helped to reduce the dominance
of Bromus inermis in the Lily's Prairie reconstruction unit

This spring, the polar vortex lingered much longer into the spring than we had anticipated it would. As a result of the late spring, we were forced to conduct an early season burn on Lily's Prairie due to the time contraints from my trip home (April 4-7th, 2014).  Our worry was that the early burn would reset our previous efforts to suppress the Bromus inermis in Lily's Prairie, because the cool season grass had not begun to grow at that point, and the early season burn would only help stimulate its growth.  By stimulating the Bromus inermis, we thought that it would cause the native forbs that have been developing in the prairie to be outcompeted and not flower, set seed, etc.  However, the results have been much different than we had anticipated...

Yellow Coneflower (Ratibida pinnata), Black-Eyed Susans (Rudbeckia hirta), and various other
non-flowering forbs are developing nicely this year after the early season burn.

My guess is that the late-season burns that we have been conducting has helped suppress the growth of Bromus inermis over the past few years.  Additionally, it appears that the native forbs have been in the development stage the whole time, and by allowing them to start early this year (due to the early season burn), they were able to tap into more energy reserves and flower at a more prolific rate.  Whatever the case, the prairie appears to be as healthy as ever.  It will be interesting to see how it continues to develop over the rest of the growing season.