The National Garden Bureau has selected 2000 as "The Year of the Sweet Corn." But every year should be the "Year of the Sweet Corn."
Summer just is not summer without this tasty treat on the table. You will never get any treat more delightful than corn fresh from the garden.
Corn is only found in a cultivated environment. A wild grass, Teosinte (Zea mexicana) is the ancestor of all known species and grows wild in remote areas of Central America. (The oldest known remains of corn are 7,000 years old.) Columbus is credited with bringing corn to Spain when he returned from the Americas in 1493. (I think corn is the reason Europeans referred to the time before Columbus' discovery as the Dark Ages. What did they serve at barbecues and picnics? How could they ever know happiness without running their teeth around a juicy cob of corn?)
As trade routes spread around the globe in the 1500s, so did the popularity of corn.
In the 1700s, American Indians cultivated flint (or field) corn and shared many different varieties with the English colonists. In 1779, the first recorded sweet corn, Papoon, was a white-kernel corn collected from Iroquois Indians. In 1821, a Connecticut seed company listed sugar corn — another white-kernel corn — in its catalog.
James Vick's "Flower and Vegetable Garden Book," published in 1880, listed many sweet corn varieties. He described Stowell's Evergreen as: "Magnificent late variety, keeping in eating until frost." Stowell's Evergreen was introduced in 1853, and Country Gentleman was introduced in 1890. Seed is still available for these old-time varieties. Both have white kernels, but the popularity of white corn changed in 1902 when the W. Atlee Burpee Co. introduced Golden Bantam, one of the most popular varieties ever.
The first hybrid, Redgreen, was released by the Connecticut Agricultural Experiment program in 1924. Golden Cross Bantam, released by Purdue University in 1932, is still widely planted.
Scientifically, sweet corn is Zea mays regosa. The genus Zea is Greek for some cereals, the species mays is a different spelling for maize (or corn), and the variety regosa means wrinkled and refers to the mature seed.
There are six major categories of corn. Gardeners are most interested in Zea mays regosa, or sweet corn. Other types of corn include popcorn, which explodes when heated; genetic dwarf or midget corn, which features mature ears at 4 to 6 inches in length; broom corn, which is grown for the long fibrous tassels used for making brooms or dried arrangements; field corn, which is called dent corn because of the hollow space on the top of dried kernels; dent corn is used for animal feed, oil and sweeteners; and the decorative, multicolored flint or Indian corn.
There are three types of sweet corn: normal sugary (su), sugary enhanced (se) and supersweet (sh2). These types refer to the sugar content and sweet flavor in the kernels when mature. The normal sugary sweet corn converts kernel sugar to starch immediately after harvest. This means the sweet flavor is lost rapidly.
Supersweet types were discovered in 1950. They contain more sugar, and when dried, the kernels shrink, thus the name "shrunken two" (sh2). These high-sugar types were named "supersweet" because the sugar level can be twice as great as normal sugary sweet corn at maturity. The supersweet types converts sugar to starch slower, so the sweet flavor lasts longer after harvest.
Ten years later, sugary enhanced corn was introduced. The corn features even higher sugar levels so the flavor lasts even longer after harvest. These sugary enhanced types are very popular because they combine sweet flavor with easy growing needs.
Supersweet types are excellent eating but must be isolated from normal sugary and sugary enhanced sweet corn. The easiest ways to isolate varieties are to grow only one variety of sh2 sweet corn or grow varieties having maturity dates at least 10 to 14 days apart from the supersweet, so they will not release pollen simultaneously.
There are two ways to plant corn — in blocks or in hills.
If space is adequate, plant rows of corn in blocks of a minimum of four rows, 2 1/2 to 3 feet apart. "Block" planting ensures adequate pollination, and the rows can be as long as you want. In poor soil, raised beds are easier to establish, improve and maintain. Sow double rows on each raised bed.
For small plantings, sowing in "hills" is recommended. Hills are groups of 4 to 5 seeds sown in a circle, with 2 inches between seeds. Space the hills 2 to 3 feet apart and when seedlings emerge, thin each hill to 2 to 3 plants. For adequate pollination, 12 to 24 plants are required.
For optimum growth and production, keep the patch weeded. Hoe or pull weeds until the stalks stand 12 to 15 inches tall. Avoid damaging the shallow root system as plants grow taller. Mulch with hay, compost or other organic materials to help maintain moisture and control weeds.
Sweet corn is a heavy feeder and quickly depletes soil nutrients. Use a complete fertilizer at planting and add nitrogen fertilizer when stalks are 8 inches tall and when the tassels appear.
There are hundreds of sweet corn varieties to grow in your garden. Plant on the north side of the garden because corn plants are tall and will shade other garden plants.