Red clay soil covers more than a million and a half acres of North Carolina. It’s vital to crops and a signature part of the state’s famous pottery tradition.
So, how exactly does it get its hallmark hue? In this installment of Carolina Curious, WFDD's Paul Garber gets the dirt.
Red clay is synonymous with the North Carolina Piedmont, but it actually has a long trail throughout the broader region.
Cody Craddock, a cooperative extension agent in horticulture with the Randolph County Center, says the soil is composed of the sediment of iron-rich rocks that have weathered over time.
“Iron oxide is essentially rust,” he says. “So there's iron compounds in the soil, and when exposed to adequate levels of oxygen, those compounds, they become a red color.”
The red clay in the Seagrove area of Randolph and other nearby counties has made the region a mecca for traditional handmade earthenware pottery.
Craddock says much of the red clay soil in this area came from the erosion of the Uwharrie Mountains.
In terms of agriculture, the soil is great for certain crops like wheat and corn.
For gardeners, though, Craddock says it can be a mixed bag. Its color is an indication that the ground is well aerated. But it's not very fertile.
He says that’s led to some frustrated calls from local gardeners, but the simple solution is to add some fertilizer.
“So our soils, they're a bit of a double-edged sword,” he says. “They take some learning, especially if you don't grow up around them, to get used to, but they can be very good soils to grow in.”
A type of red clay soil, known as ‘Cecil series, is so culturally important to the region that in the 90s, the legislature named it North Carolina’s official state soil.