American Grass: Blue Grama

What Grass?

Ask the question out loud and you tend to get one of two answers, and both are wrong in instructive ways.

People who think of lawns say Kentucky bluegrass. It is neither from Kentucky nor American — it came from Europe and Asia with colonists — and almost no cattle in this country live on it.

People who think of history say big bluestem, the tallgrass that stood higher than a man on horseback and built the soil the Corn Belt has been spending ever since. That one is at least native, and it is the right answer to a different question. It is also, functionally, gone: under 4% of the tallgrass prairie survives. It is a monument, not a working grass.

The real answer comes up to your boot top. It is grey-green, fine-leaved, unremarkable to look at, and it carries a small seed head bent over like a comb or an eyelash, which is the only thing about it most people would recognise.

It is called blue grama, and it is the grass of the American frontier.

Not one grass among many out there. On the Western Shortgrass Prairie the United States Forest Service's own vegetation database puts blue grama at 75% to 90% of net primary production on most sites — three quarters or more of everything that grows. Buffalograss runs alongside it. That ecoregion covers roughly 120 million acres across Texas, Oklahoma, New Mexico, Kansas, Colorado, Nebraska and Wyoming, and blue grama's range runs far past it: most of the western states, down into Mexico, north into Alberta, Saskatchewan and Manitoba.

It is already the official state grass of Colorado and of New Mexico. Two states looked at everything growing inside their borders and picked this one.

And it fed the buffalo. Estimates of the pre-settlement herd run from 30 to 60 million animals — the figures are contested and the National Park Service publishes the range rather than a number — down to fewer than a thousand by the 1890s, by some counts as few as three hundred. Whatever the true peak was, tens of millions of large ruminants lived on the Great Plains for thousands of years, and nobody planted anything, fertilised anything, cut hay, or fed through a winter.

How It Is Built

Blue grama is not impressive and that is the point. Every feature of it is an answer to a specific way of dying on the High Plains.

Its growing points sit at the soil surface. Most grasses raise their growth from a node up the stem, which is why a hard grazing kills them — the animal eats the part the plant needed to regrow from. Blue grama keeps that part below the bite. It can be grazed to the dirt and come back.

Its roots go down about 6.5 feet and, more importantly, sideways in extraordinary density — lateral roots produced as often as 4.3 per inch, spreading twelve to eighteen inches out from a plant that may be four inches across. It is a machine for capturing a thunderstorm before the water gets away.

And it cures on the stem. When it goes dormant it does not collapse and rot; it dries standing, holding its feed value in place, which is what made deferred winter grazing possible on the plains without a barn, a baler or a hay crop. The herd walked to standing feed. That is the whole of the system that ran here for ten thousand years.

Now the honest limit, because this piece is arithmetic and not a hymn.

Cured grass is energy with the protein gone. Bison handled that by being bison — lower requirements, enormous range, and the freedom to walk to better country and to die in bad years, which is a management strategy no rancher is allowed. A modern cow-calf operation with a fixed fence line and a calving date meets the same gap with protein supplement, and that gap is real and is not a criticism of the grass.

What Happened to It

Three things happened, and the striking thing is that not one of them was an accident.

The first was the plow. The tallgrass went almost entirely, and the eastern edge of the mixed-grass with it. The conversion has never stopped: the World Wildlife Fund's Plowprint analysis, which tracks cropland expansion across the Great Plains by satellite, found nearly 2 million acres of grassland broken out for crops in a single recent year. (The 2025 edition was paused when the underlying federal data series changed, so the most recent published figure is the one above.)

The second was that we planted something else on purpose. This is the part nobody tells as a single story, and it is the same story three times.

Old World bluestem is the one currently doing damage on the Plains. At Kansas State's research station at Hays, the range scientist Keith Harmoney has measured it expanding in plots at 15% compounded a year — a doubling roughly every five years. It is allelopathic: it puts compounds into the soil that suppress the native grasses around it, and it converts diverse prairie into a single-species stand. And cattle do not much care for it, so they graze around it and hammer the remaining natives instead, which hands it the ground faster. It now turns up in just about every county in Kansas.

The third was fire. Specifically, the absence of it. The Plains were maintained by regular low-severity fire, and with fire suppressed, woody plants advance — eastern redcedar through the central and northern Plains, Ashe juniper and mesquite to the south.

This is not a slow problem. A single mature female redcedar produces up to 1.5 million seeds a year and throws them roughly 200 yards, which is 26 acres of new ground per tree. Across the Great Plains, woody encroachment is now associated with the loss of about 22.4 million tons of annual rangeland production — enough forage, by the same estimate, to carry 4.7 million cows. In South Dakota alone, tree cover increased on nearly 192,000 acres between 1990 and 2022, and land with meaningful encroachment is reported to lose 30–50% of its value.

And overgrazing? It belongs on the list, but not where most people put it. Because blue grama's growing points sit at the soil surface, heavy grazing does not remove it — it removes everything taller and leaves blue grama behind. Range science classifies it as an increaser. Arizona Cooperative Extension states the consequence plainly: a substantial increase in blue grama where it was not previously dominant is a signal that range condition is worsening. A pasture can be nearly pure blue grama and be in poor shape. What continual heavy grazing genuinely destroys is not the species but the productivity: plant height, vigour, and belowground production all fall, and they fall hardest in drought.

The Thing Nobody Measured

Of the three introduced grasses, tall fescue is the one whose full price took forty years to appear, and it is worth the detour because it is the clearest case of what this pattern actually costs.

Kentucky 31 was found in 1931 by E. N. Fergus, an agronomy professor at the University of Kentucky, on a steep poor hillside farm in Menifee County that had carried the same stand with no care at all since at least 1890. That was the recommendation: it had survived forty years of neglect on bad ground.

By the early 1950s farmers on the new grass were reporting cattle that would not gain, cows that would not breed back, animals standing in ponds in August with winter coats they had not shed, and in hard winters, lameness that could take a tail switch, an ear tip or a hoof. They called it fescue foot. In 1954 J. K. Underwood and colleagues in Tennessee noted that the signs looked like ergotism — the medieval rye disease — but found no ergot bodies in the grass and let the thread go.

It was picked up by a USDA chemist at the Russell Research Center named J. D. Robbins, who did not believe the coincidence. There was a farm near Mansfield, Georgia, where cattle on one fescue pasture were visibly sick and cattle on three adjacent pastures were fine — same farm, same water, same weather, same management. Robbins was refused permission to make the trip. He went anyway, on 13 June 1973, and sampled the pastures himself.

His colleague C. W. Bacon put the samples under a microscope and found a fungus living inside the leaf tissue. In the pasture where the cattle were sick, 100% of the plants were infected. The paper appeared in Applied and Environmental Microbiology in November 1977.

Kentucky 31 had been planted across a third of the eastern United States for thirty years before anyone knew what was in it.

The fungus is not a disease of the grass. It is a partner, passed inside the seed, and it manufactures the plant's defences — including a family of ergot alkaloids, principally ergovaline. Those compounds are precisely why the grass survived forty uncared-for years on that hillside. In a cow, ergovaline mimics dopamine closely enough to bind the receptors, producing sustained constriction of the blood vessels and shutting down prolactin. That is the animal that cannot shed heat in August, cannot keep blood in its feet in January, milks poorly and does not settle.

The costs, which are estimates and should be read as such: the University of Missouri has long published $609 million a year on 1990 data; Missouri's own fescue programme has used $900 million; a 2022 review in Animal Frontiers puts it at approximately $2 billion annually. None of them publishes a derivation, which is worth saying rather than picking the largest and running with it. The order of magnitude is not in dispute, and most of the loss is in calves that were never conceived rather than pounds that were never gained.

Recent sampling reported by Virginia Cooperative Extension found 100% of pastures tested infected, 80% at infection levels of 70% or higher, and total ergot alkaloids averaging 1,543 parts per billion against a commonly cited disorder threshold of about 400. Nearly four times over, on effectively every pasture sampled, half a century after Robbins drove to Mansfield without permission.

One qualification, stated plainly: fescue toxicosis is a disease of the grazing animal. The entire literature on it concerns what happens to the cow in the pasture. This is a production story, and it makes no claim about food safety in either direction.

Why It Kept Happening

Here is the uncomfortable part, and the reason this is not a story about villains.

Every one of those introductions won on the numbers. Not marginally. On every measure an agronomist of the 1930s or 1940s was trained to take, the imported grass beat the native one, and the margin is still there today.

In the depth of winter, the European grass carries roughly twice the protein of the native one and clears the requirement of a lactating cow, while the native clears nothing. It also yields several times more per acre, grows in the cool shoulders of the year when warm-season natives are dormant, and holds a bank on a gully in a single season.

The frontier grass did not lose to a worse grass. It lost to a better one, judged by the only measures anybody was taking.

What nobody was taking was a measure of what the grass does inside the animal across a decade, or what a single-species stand does to the ground across fifty years. There was no column for that. Extension bulletins reported tons per acre and protein percentage, because those are the things you can weigh by Friday.

So the land-grant universities released, the extension services promoted, the conservation agencies seeded, and the cost-share programmes paid — every institution operating correctly with the information it had. The Soil Conservation Service put crested wheatgrass on a landscape that was physically blowing away, and it worked. Kentucky 31 held gullied Appalachian hillsides that were beyond anything else, and it worked. These were not mistakes at the time. They were successes whose full invoice arrived decades later, addressed to somebody else.

What Is Left, and Who Has It

The last turn in this is the one that surprised us in the reporting, and it is good news arranged in an awkward shape.

The shortgrass prairie did not go. Roughly 56% of that ecoregion's habitat outside protected areas remains essentially intact — and under 1% of the whole ecoregion is formally protected, meaning the intact half is not protected land at all. More than 90% of America's Great Plains grasslands are privately owned. The Nebraska Sandhills alone run to 19,000 square miles and are counted among the two most intact temperate grasslands left on earth.

It survived for an unromantic reason: it was too dry to farm profitably, and the Dust Bowl was the demonstration. Where the rain was good enough to grow something else, the native grass is gone — plowed for row crops in the tallgrass, replaced with an import in the fescue belt. America kept the grass it could not farm and lost the grass it could.

Which means the last great American grassland is standing on private cattle ranches, and it is standing because they are cattle ranches. The single land use that has preserved the frontier is the one that keeps grass as grass because an animal eats it. Every alternative on that ground — row crops, subdivision, energy — ends the grassland. Grazing is what has kept it.

And the people holding it have no instrument. No futures contract, no basis, no hedge, no price series, and an insurance product that pays out on a rainfall grid without ever inspecting the pasture. They carry the asset and the risk of the largest feed input in the country, and the market has never issued them a receipt for it.

A direct trade does not fix that, and we will not pretend it does. It does one small thing: it pays a producer for what a specific piece of ground actually produced, rather than for a grade average struck a thousand miles away. That is not a market for grass. It is at least a number attached to some.

No Ticker

Blue grama has no seed company pushing it, no cost-share programme behind it, no extension campaign, no delivery month, and no line in anybody's accounts. Nobody released it and nobody improved it. It has never been anyone's product.

It simply happens to be what this continent grows, on the driest and hardest third of it, and it was doing the job before there was anyone here to name it — short, grey-green, rooted six feet down, cured standing through the winter, waiting.

It is the American grass. It is also the only one the market has never found a way to charge for.