Corn

Sugary sweet corn fresh from the garden is a favorite vegetable of many people. In addition to its fine flavor, sweet corn is a source of carbohydrates and food energy and it contains some vitamin A (yellow corn only), minerals, and protein. Besides its popular use as corn-on-the-cob sweet corn can be used in scalloped dishes, succotash, relishes, fritters, soups and chowders. Many, but not all, sweet corn cultivars and hybrids are acceptable for freezing.

In the Northeast, the sweet corn season beings about July 1 and continues until the first frost (late September or early October). Fresh sweet corn is most plentiful, however, from July 20 to September 15. Top-quality sweet corn ears have fresh, green husks, and ears well filled with bright-colored, plump, and milky kernels. The ears should be free of insect and disease damage.

Cultivars and Hybrids

In addition to the well-known cultivars and hybrids, some excellent whitekernelled types are available as well as hybrids with bi-colored ears of both yellow and white kernels and extra-sweet types. In addition to differences in color of kernels, corn cultivars and hybrids vary in the amount of time required to mature a crop (from 60 to 90 days). By planting seeds of early, mid-season, and late-maturing cultivars on the same day, the gardener can extend the sweet corn harvest season over a period of several weeks. The harvest season can also be extended by planting seeds of one cultivar or hybrid at 10 to 14 day internals to get a succession of crops.

Some of the sweet corn cultivars and hybrids that grow well under Northeast growing conditions are: Early and Medium Early: Earliking, Spring Gold, Bravo, Sundance, and Aztec ; Mid-season: Gold Cup*, Golden Cross Bantam*, Seneca Chief*, Victory Golden*, NK-199, Jubilee*, Merit, and Sugar Loaf; Late: Honeycross, Iochief*, and Silver Queen* (white); Mixed White and Yellow Kernels: Honey and Cream, Butter and Sugar, Gleam and Gold, Sprite, Sweet Sue, and Sweet Sal. Types other than these may grow well in the home garden and the gardener may want to try several different kinds to determine which best fits their needs.

*Suitable for freezing or canning.

Climatic and Soil Requirements

Sweet corn, a warm weather crop, grows best when temperatures range from 60–80oF and the soil is well supplied with moisture. Adequate soil moisture is especially 2 critical at silking time and when kernels are forming. Water-logged or poorly drained soils are to be avoided as root decay and resulting poor plant growth may result. Sweet corn plants will grow in a variety of soil types but growth is best in fertile, loamy, well drained soils of pH 5.8 to 6.5. Sweet corn plants grow best when exposed to full sunlight throughout the day; shady areas should be avoided.

Fertilizers

Fertilizer and lime are best applied to the soil using the results of a soil test as a guide. The fertilizer should be applied 2–3 inches to the side of and slightly below the seed. Contact of fertilizer with the seed should be avoided as germination may be reduced or seedlings injured. Satisfactory fertilizer analyses for sweet corn are 12-12-12 and 6-24-24. Applications of 15–20 pounds per 1,000 square feet are commonly made in growing a sweet corn crop in the home garden. A side-dressing of one to two pounds of a fertilizer such as 8-16-16 or 12-12-12 per 100 feet of row when plants are 12–25 inches tall is a desirable practice.

Planting

Sweet corn should be planted after the danger of frost is past. Plant seeds 1–2 inches deep and 9–12 inches apart in rows 30–36 inches or more apart as necessary to accommodate cultivators. Use the deeper planting depth in dry soils, the shallower depth when soil is moist. Four ounces of seed will plant a 100-foot row. It is suggested that several short rows be planted rather than one long row so that pollination can occur more readily. A yield of eight to eight and a half dozen ears may be expected per 100 feet of row. As the sweet corn crop requires considerable growing space the crop may not be as productive in the small garden as other vegetables.

Cultural Practices

For best results the crop should be kept free of weeds. Cultivation should be shallow when the weeds are small to avoid damage to plant root systems. Supplemental watering is recommended during periods of insufficient rainfall. The plants require at least one inch of water per week when temperatures are warm and growth is rapid. Mulches may be used to conserve soil moisture. Suckering or the removal of basal side shoots from the plants is unnecessary; some cultivars and hybrids are more likely to develop suckers than others.

Insects and Diseases

The most common insect and disease problems of sweet corn are the corn earworm, corn borer, sap beetle, bacterial wilt or Stewart’s disease, and smut.

Harvest and Storage

Sugar loss from harvested sweet corn is rapid at high temperatures so the crop should be cooled as quickly as possible after harvest. If the fresh product is to be kept for any period of time after harvest it should be kept in a moist environment and at a temperature as close to 32oF as possible

Adapted from James D. Utzinger, Ohio State University, 2001