Prairie Reconstruction – Addendum

Addendum to “An Attempt at Prairie Reconstruction”

While a typical prairie reconstruction in tallgrass regions generally involves more or less a hands-off approach for the first few years, followed by a burn during the 3rd or 4th year, I took the unconventional route of mowing the second year prairie down to bare soil just before greenup.  This did two things: 1.) It re-started secondary succession, allowing for more annual showy plants, and 2.), it subsequently allows for equal sunlight across the planted area, resulting in warmer soil temperatures than the surrounding area, encouraging an earlier greenup of prairie species, and creates a free-for-all competition amongst the newly emerging seedlings.

After the mowing, I dragged the area with a chain drag harrow to disturb the soil to a depth of an inch, taking care not to uproot established perennials.  I also overseeded with my seed mix (140 species now, up from 72 spp. during last year’s inaugural seeding) and then dragged the chain harrow over the area again to lightly “rake in” the seeds.  There was one stark difference compared to last year’s seeding on the same spot – the abundance of Silphium seedlings.  Such a sight is uncommon anymore in the Western Cross Timbers due to overgrazing and overmowing.

Two other reasons I mowed earlier than normal was to kill the first flush of juvenile annual Crabgrass (Digitaria sanguinalis) seedlings (of which there are thousands),  and to temporarily set back the aggressive Bermudagrass (Cynodon dactylon) before spraying both species with the grass-selective Fluazifop-P-Butyl (“Ornamec 170”, “Grass-B-Gone”, etc.) this month.  It is my first time using such an herbicide and I am curious to see how effective it is.  Two setbacks for the Bermudagrass and Crabgrass in 5 weeks’ time should help with overall control efforts.  More than likely two or three more herbicide applications will be needed, especially for the Bermudagrass.

However, the areal coverage of Bermudagrass has been reduced by approximately 85% (visual observation) within the inaugural prairie reconstruction site. In the expansion areas, it largely died out in the droughts from the years before or was killed during last year’s second glyphosate application (20% solution).  In the areas under that treatment the Bermudagrass is still dead, but its stifling semi-decomposed thatch layer still remains, suppressing any further expressions of what the seed bank may hold.  The Bermudagrass will never be 100% eradicated, but with current reduction rates and continued chemical and mechanical control, along with aggressive plant competition from the members of the young prairie, I no longer worry about Bermudagrass like I used to.

The backyard prairie started at 285 square feet in January 2014.  It now occupies 1,100 square feet.  Another 500 square foot expansion is planned for later in the year.

Some might ask or suggest, “Well, why not try and sod with native plants?” Prairie sod exists as a niche product within a small market, has limited commercial availability, high up-front consumer costs (shipping and installation) and production costs (growing, weeding, and harvesting) when compared to direct seeding and seedlings.  Direct seeding will always be the most economical and preferred option.  More species can be established via seeding than sodding.  I am unaware of any producers in Texas or Oklahoma who will grow custom high-diversity prairie sod using a customer’s own seed or specified seed mix.

Furthermore, I would rather partition some of the overall costs involved towards killing and controlling the aggressively rhizomatous exotic species, Bermudagrass (C. dactylon) and Johnsongrass (Sorghum halepense) – which has yet to invade the prairie but is close enough to be of concern – than to opt for sod and hope for an “instant prairie”, which does not exist.  It is my opinion that direct seeding and seedling installations allow for a more flexible prairie that is better able to respond to today’s environmental pressures, and produces a far superior visual demonstration of plant succession, which is a critically important component of prairie restoration and reconstruction. Laying prairie sod may produce quicker areal and visual results, and may keep complaints of neighbors at bay, but it is artificial, given it’s a hallmark product of the turfgrass industry.

Sodding, because of its association with high-maintenance urban lawns, lends itself to a disconnect from prairie restoration and creates far fewer opportunities for hands-on education about the individual prairie members, as opposed to greenhouse grown seedlings or naturally established seedlings.  Neither does sodding show the true strength of the prairie community like a seeded prairie demonstrates though its genesis and subsequent ecological succession.

The emerging prairie in its vernal, early successional aspect.  Note the abundance of Common Sunflower (Helianthus annuus).  Other abundant annuals are Plains Sunflower (Helianthus petiolaris), Horsemints (Monarda punctata and M. citirodora), Black-eyed Susan (Rudbeckia hirsuta), and the seemingly abundant forb germinating from the seed bank at this site, Redroot Pigweed (Amaranthus retroflexus).
The emerging prairie in its vernal, early successional aspect. Note the abundance of Common Sunflower (Helianthus annuus), an excellent native nurse plant. Other less abundant annuals are Plains Sunflower (Helianthus petiolaris), Horsemints (Monarda punctata and M. citirodora), Black-eyed Susan (Rudbeckia hirsuta), and the seemingly abundant forb germinating from the seed bank at this site, Redroot Pigweed (Amaranthus retroflexus).  The plant with the blue pin flag (upper right corner) is Big Bluestem (Andropogon gerardii), which was already over a foot in height when the picture was taken.
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