I walked through a stand of prairie grasses and flowers out at Hickory Grove Park yesterday. Ripening seed heads of native grasses and flowers surrounded me as I recalled the day that stand was planted about 35 years ago. The site was a cornfield before it became part of the park in the late 1960s, and no native plants were present. I remembered mowing that area like turf grass the first summer I worked for the board back in 1973. The site was prepared for conversion to prairie around 1980, early in the spring, by first burning off the old growth and then spraying the regrowth of alien grasses and weeds with Roundup. The conservation board was still buying commercially produced native grass seed back then, but seed for the flowering plants (forbs) had been hand-harvested from local remnant prairie areas the previous fall by a corps of volunteers. Around 20 kinds of precious flower seeds were added to the hopper of the Truax native seed drill. Several pounds of seed from common flowers like yellow coneflower and sawtooth sunflower were available, but less common plants like lead plant, compass plant, and butterfly milkweed were represented by only a few ounces.
We raced to finish planting before thunderheads building to our west broke over us. Heavy rainfall began shortly after we finished late that afternoon. And then we waited. The weeks of summer slowly dragged by and we kept the newly planted area mowed so that new sprouting prairie plants could get all the sunshine they needed. It didn’t look like much that first fall, but we were able to see rows of little native grass plants and few baby prairie flowers. The second summer was glorious, with waves of golden black-eyed susans. The first heads of prairie grass waved in late summer breezes, but most of the prairie flowers we had planted were nowhere to be seen. The third summer had fewer black-eyed susans, but yellow coneflowers put on quite a show. Sawtooth sunflowers and tall prairie grasses filled in more of the stand by late that summer.
We burned the area in the spring prior to the fourth growing season. We had already learned that fire could work magic on native prairie, and we weren’t disappointed, as a few new flowers began to show up that summer. Fire was applied every few years, but it took even more years for some of the flowering plants to show up. Lots of sawtooth sunflowers are still part of that little prairie reconstruction. That’s what we call planted stands, as opposed to native prairie remnant stands. Black-eyed susans are seldom seen now. Yellow coneflowers are still there, but are fewer in number than they were in the first few years. Plants like round-headed bush clover and early blooming golden alexanders continued to increase as the years went by, and a regular visitor this past summer would have noticed bright orange butterfly milkweeds, spikes of pure white wild indigo, deep blue-purple lead plants, tall yellow compass plants and even a few feathery pink blazing stars. Most of the precious prairie flower seeds that were hand-harvested so many years ago have finally shown up with at least a few blooming plants.
The techniques used for planting prairies today are similar to what we did on that early reconstruction. They continue to be modified as nature teaches what she likes best, though. Fires occur in the fall as well as spring, now, and prairies may be planted around Thanksgiving or Easter (a “frost seeding”) more often than they are around Memorial Day. Plants that can trace their ancestry to local remnants are called local ecotypes. We began using local ecotype flower seed early on, because commercial flower seed was so expensive and because we had a growing corps of volunteer hand harvesters to help us. We now know that local ecotype plants are better suited to our local growing conditions. Some seed is still purchased from commercial sources, but even grass seed on most reconstructions done in the past 15 years now claims local genetics. 1950s and earlier vintage Allis Chalmers combines have been painstakingly modified and maintained to harvest mixed stands of prairie grasses and flowers from wild remnants and reconstructions, but volunteers still hand-harvest some of the seed that’s used.
A good native remnant the size of that little reconstruction at Hickory Grove Park might support 100 or more species of of native plants. Doolittle Prairie, a larger state preserve south of Story City, hosts more than 200 species. Recent planting efforts may include 50 or more species, but the roughly 30 species of native prairie grasses and flowers present on that early reconstruction at Hickory Grove still represents a very successful planting. We may never be able to duplicate nature’s amazing diversity, but new plants continue to appear for years as planted stands mature. We will be walking through what looks and feels like a real native prairie later this morning as volunteers hand-pick seeds descended from the efforts of an earlier generation of conservation volunteers. We’re still learning how to make the best use of their efforts, too.
Steve Lekwa is a former director of Story County Conservation.