I harvested my northern drop seed grass last weekend. The panicles were full of seeds, all but two, which had already dropped theirs. The 20 or so flowering stalks on the three plants will produce a couple of tablespoons of cleaned seed.

This will be mixed with seeds from more than 100 other prairie plants and sown, by various methods, into one of five prairie and savanna remnants along the North Branch of the Chicago River.

The prairies and savannas are tended by the North Branch Prairie Project, an organization with more ramifications than the root system on a 50-year-old northern drop seed. The particular ramification that accounted for the presence of three northern drop seed plants in my backyard is a prairie gardening program that is the exact botanical equivalent of a captive breeding program for wild animals.

The NBPP started 11 years ago with a plan to restore several degraded prairie remnants along the North Branch. The sites range from Somme Woods at Dundee and Waukegan roads at the northern edge of Cook County to Bunker Hill Woods, which is within the city limits of Chicago.

You can rank prairies along a qualitative scale ranging from very high quality to degraded. The highest quality sites would have many prairie plants and few Eurasian weeds. Degraded sites turn that ratio around. Along the North Branch, the prairie was just hanging on. The weeds occupied most of the space, and they were expanding, with the pestiferous shrub called European buckthorn leading the charge.

After 11 years of hard physical labor, the tide has turned on the North Branch. The prairie and savanna systems are plainly reclaiming their ancestral lands. Rattlesnake master and shooting star now bloom where once there was nothing but the stygian gloom of a buckthorn thicket.

The (thus far) victorious strategy of the NBPP had several parts. First there were the workdays, once a week through nearly the entire year, cutting buckthorn, felling small box elders and girdling the bigger ones, pulling up whole fields full of white sweet clover–which is a job you couldn’t pay people to do–and raking prairie seeds into the soil.

And then there were the fires, once a year if the weather cooperates, the flames burning out weeds and freeing land for the young prairie.

And then there was seed gathering to supply the work crews with the seeds they needed. You can get some prairie seeds by mail from nurseries as far away as Nebraska, but Nebraska plants are not Illinois plants. Preserving the Illinois prairie means preserving as much as possible of the actual gene pool, the local ecotypes and varieties that evolved in this place. You can’t do that with seeds from Nebraska.

So, staying within 15 miles of the North Branch prairies, volunteers searched the roadsides and railroad tracks for unprotected scraps of prairie. Throughout the summer, fall, and winter, they collected seeds from these unprotected sites and sowed them on the North Branch.

But unprotected prairies tend to disappear. Nearly all the harvest sites have now vanished under the bulldozers. So a couple of years ago, the NBPP decided to try to grow its own seeds. Hence, the captive breeding program.

Natural gardening has become a bit of a fad. Dense tangles of wildflowers are replacing lawns in some gardens. Some zealots turn their whole yards into prairies, often to the outrage of their more conventional-minded neighbors. We have a huge wildflower garden in Grant Park, an excellent conception that was unfortunately executed with a mix of species that will require endless labor to maintain.

Prairie flowers can do a lot for your backyard, but the main interest in the captive breeding program is seed production. We’re talking crops here, not pretty flowers.

In the beginning, volunteers signed up to accept small packets of seed to be planted in their yards, but this proved to be a rather unproductive way to do things. I got the seeds for five different species. I kept them in the refrigerator all winter to simulate life in the outdoors, and in the spring I planted them.

Nothing came up. Tiny seed leaves peeked above the ground, and we watched them hopefully until the emergence of the first real leaves exposed them as lamb’s quarters or bull thistles or some other vile weed.

Growing wild plants is tricky. If you plant tulip bulbs or nasturtium seeds, you are planting something that has been selectively bred for hundreds of generations. The bulbs all sprout on the same day in spring; if the seed packet says “germinates in 10-14 days,” you can be sure it will happen.

Also, some of their seeds may sit for four or five years before they sprout. And each plant has its idiosyncrasies, quirks we can only guess at. Preston Spinks, a Morton Grove man who has been involved with the NBPP for several years, seems to have the knack to overcome these problems. He has successfully grown dozens of species, and rootlets from his garden (the plants grow for one year and are dug up for transplanting during the winter when they are dormant) will now be the main source for future gardeners.

I got my three northern drop seed grass plants from Larry Hodak, another prairie gardener who had enjoyed some success. They were thriving when I got them. All I had to do was put them in the ground.

The other major gardeners are mostly people with long years of experience working around the prairie. Pete Baldo has a gorgeous prairie garden that supplied most of the blazing stars that now provide such a rich display at Somme Woods in midsummer.

Ross Sweeny, another longtime volunteer, has a garden of no less than 30 northern drop seed plants. He has more plants of this species in his backyard than the North Branch prairies had growing wild ten years ago.

Northern drop seed gets so much attention from the captive breeders because it is in some sense the ultimate prairie grass. It is a low-growing plant that consists mainly of a tuft of long, slender curving or arching blades. Old ones, and they may live for centuries, are as big as hassocks. The flowering stalks grow out of these tufts and stand above them.

In early Illinois, drop seed was a common grass, but it began to decline as soon as settlers arrived. Cows loved it, for one thing, and settlers didn’t particularly care for it. It is quite aromatic, and the odor has been described as smelling like sex. Maybe our straitlaced Victorian ancestors couldn’t stand having this licentious grass around.

Today, it is found only on prairie remnants of the very highest quality. Indeed, its presence is in itself a sign of high quality.

Its status is a product of its place in the process of succession. Every sort of natural community has a typical succession pattern. A prairie swept bare by some catastrophe would be invaded first by annuals, shallow-rooted, fast-growing species like ragweed that produce seed in their first, and only, season of growth. But in time, the longer-lived species would establish themselves. Perennials begin each season supported by the energy collected last year, and they can outcompete any plant that has to start from scratch every spring.

The endpoint of this process is domination by a group of plants that are superbly adapted to very stable conditions. Their strategy is to take it slow. Live a long time. Get hold of some space and sit on it for a couple of centuries. Put off having children until your root system is well established and then don’t have very many. You’ve got centuries to replace yourself, so why throw all your energy into seed production.

This is how northern drop seed got to be a dominant grass in Illinois. And this is why the species has done so poorly since 1818. To live around humans, you need to be quick and opportunistic, like ragweed.

As of 1987, northern drop seed was established in small numbers on all the North Branch prairies, but the largest population at any one site is only about 30 plants. Relying on these wild plants, it would take centuries for drop seed to become a dominant at any site.

But gardeners can speed up the process. My plants produced seed in just three years. Six years would be typical for wild plants. Of course, my plants are well watered, protected from competition, and even fed manure. Ross Sweeny gives his a shot of Miracle-Gro every week.

Thanks to these heavily interventionist strategies, we are now collecting at least a quarter of a kgb of cleaned seed every year. A “kgb,” or kitchen garbage bag, is a standard unit of measure on the North Branch. When the project got under way, half a cup of seed was considered a rich harvest. Soon, the smell of sex may return to our fields.