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Great Corn Varieties for the Home Gardener
By Barbara Melera
One of the greatest gifts that the New World presented to the Europeans was corn, or maize as it was then called by some. One of the first sights for Christopher Columbus’ crew as they reached Hispaniola was of fields of maize growing on the island. The cultivation of corn in the New World is one of the most ancient of traditions. Corn was grown from Brazil and Chile to as far north as southern Canada. It was a key ingredient in the diets of the Aztecs, the Mayans, and the Incans, and even before these civilizations appeared, corn was cultivated by prehistoric peoples of the Americas. Corn is believed to have originated from a wild grass called teosinte. The word teosinte literally means “God’s corn.” Teosinte still grows as a wild grass in Mexico, Honduras, and Guatemala. Even today, it is so genetically similar to primitive types of maize that the plants frequently cross-fertilize. Interestingly, our modern corn has become such a specialized food product that it cannot survive without cultivation by humans. 14
WASHINGTON GARDENER
APRIL 2022
There are at least six types of corn. Dent corn has kernels that have an indentation on their tops and contain soft, starchy corn under their indented tops. Flint corn has very hard kernels that are tough to grind when dried. Flour corn has soft kernels that are very easy to grind. Popcorn kernels burst open when heated. Pod corn, which is not well known and seldom grown today, produces tiny husks on which grow multicolored kernels. It is largely a curiosity and only of ornamental significance. Sweet corn, the kind with which most of us are familiar, differs from all the other types of corn because the kernels lack the ability to instantly convert sugar into starch. This is why sweet corn retains its sweet taste for a short time after it is harvested. Sweet corn is produced by isolating the plants so the recessive genes, which code for sugar and tenderness, shine through. Three recessive genes code for different kinds of sweetness and kernel toughness: SE, SU, and SH2. SU sweet corn varieties, referred to
as “normal” or “standard,” contain primarily the SU gene for sweetness. This genotype of sweet corn was the primary kind available until the last century. ‘Silver Queen’ is an example. These varieties have a sugar content of about 9 percent and the sugars convert quickly into starch, which means narrow harvest windows and limited storage ability. SE sweet corn varieties are labeled “sugar-enhanced” or “sugary enhancer,” because they contain SE genes. This genotype has increased (16 to 18 percent) sugar, with more stable sugar levels than normal sugary types. It has the ability to convert sugar to starch; that just takes longer because they start with a higher level. These varieties have a good flavor and hold better than the SU genotype. However, the skin of the kernel is quite tender and care must be taken in harvesting and handling so kernels are not damaged. The SH2 corn varieties are most often referred to as “supersweet” or “shrunken-2.” These varieties possess the SH2 gene. These genotypes provide kernels with high sugar content (about
