Glass Gem Corn

Recovering Indigenous varieties of corn results in stunning discovery

Every year when the seed catalogs arrive, I open to the heirloom corn page and swoon in delight. There are so many colorful varieties with interesting histories, but the most gorgeous is glass gem corn—showing off a rainbow of gleaming colors that are too brilliant to be real, yet they are.

Glass gem is a type of flint corn (Zea mays) that has a hard outer layer covering each kernel to protect the endosperm. Native peoples grew “hard as flint” corn because it held up in freezing temperatures due to its low moisture content. It also could be stored for long periods, making it a staple in the pantry when other food was scarce.

Evidence of corn cultivation can be found dating to 1,000 B.C. It was originally domesticated in Mexico through years of selective breeding that transformed wild teosinte grass with tiny grains into the corn we are familiar with today.

Unlike sweet corn, flint corn is too hard to be eaten fresh and is best suited for hominy, ground into corn meal, made into masa or popped for popcorn. While it would be terrific to have rainbow colored popcorn, unfortunately, when popped, glass gem corn (or any other colorful heirloom) turns the familiar white or light yellow.

Traditionally native corn was grown along with beans and squash, the seeds planted at the same time, directly into the earth to grow symbiotically together. In this system, the corn made a tall trellis for the beans to grow on. The beans in turn provided nitrogen to the soil, feeding both the corn and the squash. The squash utilized horizontal growing space between the corn and beans. These staple crops—known as the Three Sisters—could all be stored for sustenance in the winter. Together they provided carbohydrates, protein and fats—the building blocks of a balanced diet.

Glass gem corn evolved, over many years of kernel selection for the brightest and prettiest colors, by Carl Barnes, a half Cherokee plant breeder in Oklahoma. When he planted older varieties of corn, he would notice some of the colorful ancestral kernels in his corn crop. He isolated those particular kernels and replanted them, finding the resulting plants matched traditional corn varieties that had been lost to local tribes.

Barnes made it his life work to collect and trade seeds, reintroducing heirloom strains to Native elders—for whom corn represented their cultural and spiritual identity. They were so grateful that they gave Barnes the spiritual name White Eagle for his contributions to their ancestral culture. His mantra was: “The seed remembers.”

In the process of recovering lost heirloom corn varieties in the late 20th century, he developed glass gem corn, which shines in many hues like rainbow glass beads. The variety has only been available commercially for the past few years.

Like opening a treasure, shucking an ear of this corn will always delight and surprise because no two cobs are the same. Sea to Sky Farm in Santa Cruz grows glass gem corn to sell for use in fall displays. Coowner Chris Laughlin loves the corn because the stalks are a pretty purple hue and each cob is unique and colorful. She planted more this season because last year all her stalks and corn sold before she could bring them to market. Look for glass gem corn at local farmers markets this fall. If you get your hands on some, you too can save the seed and plant it next spring, keeping this remarkable variety alive.