Who plants a pecan tree?
Sometimes a person does. Sometimes a squirrel does it by mistake, or a crow drops one on the way home, or a river carries a nut a few miles downstream and leaves it in the mud. All four of those grow into the same kind of tree — the kind USDA puts on the line this quiz counts.
A pecan is a seed, and a seed only has to get somewhere. Oklahoma State University’s extension fact sheet on pecans names the delivery service: “Squirrels, crows and blue jays are still major dispersers of pecans. They prefer pecans to other hickories and oaks.” Each one works differently. Squirrels are the forgetful ones — “Squirrels can hoard up to 25 pounds of pecans a year, but many forgotten pecans grow into trees.” Crows go furthest: they “store their pecans along fencerows and forest edges and can carry pecans several miles from the tree.” Blue jays are clumsy in a useful way — they “hold the pecan while cracking the shell, accidentally dropping pecans along fence lines and trees.” And then there is the river, which does not forget anything but does carry things: “When pecans fall near waterways, they can be washed into creeks, tributaries and rivers and can travel many miles from their origin.” USDA’s own plant guide for the pecan records the same two carriers in one short line about how burnt ground gets its trees back: after a fire, it says, the pecan returns from “seeds carried to the site by animals and water.”
Basis: Oklahoma State University Extension, fact sheet HLA-6261, “Plants in the Classroom: The Story of Oklahoma Pecans” by Shelley Mitchell (September 2020), section “Natural Dispersal of Pecans”; USDA NRCS National Plant Data Center, Plant Guide, “Pecan — Carya illinoinensis,” section Adaptation. Quotations unchanged.
The map of these trees is a map of rivers, too. The USDA plant guide is precise about it: “Pecan is native from Iowa to Indiana to Alabama, Texas and Mexico,” and “This tree follows the river basins very closely, principally along the Mississippi and its tributaries, the Colorado River in Texas, and along some of its tributaries in Mexico.” It likes the low wet ground nobody else wants: “It appears near river bottoms and on heavy textured soil.” People have been eating these nuts for a very long time — the Oklahoma fact sheet reports that archaeologists working near the Rio Grande “calculated that humans have been eating pecans in North America since at least 6,750 BCE” — and one line in it is worth stopping on, because it is about the state in the quiz. “When the Cherokee were forced to move in the 1830s during the Trail of Tears, they settled along the Arkansas River. They cleared land to plant crops but left the pecan trees.” Clearing a field is a decision about every single tree in it. Some of the trees standing in Oklahoma river bottoms are there because somebody chose not to cut them down.
Basis: USDA NRCS National Plant Data Center, Plant Guide, “Pecan — Carya illinoinensis,” sections Distribution and Adaptation (the range statement cites Dirr 1990); Oklahoma State University Extension, HLA-6261, sections “Pecans and Native Americans” and “Habitat and Early Spread of Carya Species.” Quotations unchanged.
So why does anyone bother planting pecans at all, if squirrels will do it for free? Because a seedling is a lottery ticket. “Just like people, pecans are not clones of their parents; planting seeds from a strong tree with bountiful harvests of quality nuts does not guarantee similar traits in the offspring,” the Oklahoma fact sheet explains — and you wait a very long time to find out what you got, because “pecan trees do not start producing nuts until they are between 15 and 20 years of age.” The fix is grafting: “Grafting is the process of taking the most desired parts of different plants and joining them so they will grow as one,” with the roots below called the rootstock and the piece joined on above called the scion, so that “The top part of the grafted tree will be a clone of the desired tree.” It also skips most of the waiting: “grafted pecan trees start producing at six to eight years of age.” That is the whole difference between USDA’s two pecan lines: grafted, or not grafted. One is a copy of a tree somebody picked out. The other is a brand-new mix of its parents. And note what the two lines do not record — whether anyone planted the tree. A nut a farmer pushes into the ground grows a seedling just as much as a nut a squirrel buries, and the same Oklahoma fact sheet says that long before either, “many tribes probably planted and tended pecan groves.” So the second line is not a line for wild trees. It is a line for trees nobody made a copy of.
Basis: Oklahoma State University Extension, HLA-6261, sections “The Beginnings of Pecan Crop Uniformity” and “Pecans and Native Americans.” Quotations unchanged.
Why is Oklahoma’s the biggest area of this kind of tree, though? The fact sheet gives good reasons the trees were never cleared — the riverbank land flooded and was no use for cotton, and the wood was no use to loggers — but those reasons are just as true in Texas, Missouri, Arkansas and Louisiana, which are all on the same list, further down. Something in the shape of that state’s rivers, or in what was planted beside them, or in who kept which fields, would have to finish the explanation, and none of the sources used here finishes it. There is also a quieter possibility worth holding on to, and it is about counting rather than about trees. This table records land that a farm reported as bearing pecan acreage. A wild grove only appears in it if somebody is treating it as part of a farm at all. So the ranking may be measuring which state has the most ungrafted pecan trees, or it may partly be measuring where unmanaged groves are most often counted as farmland — and from the table alone there is no way to tell those two apart.
※ A hypothesis is an idea that isn't proven yet.
📊 Sources for the rankings mentioned in this note (links to the original data and retrieval dates) are on each quiz page below.