Varieties of Sweet Corn

Sweet corn is a great vegetable to grow in your garden, and there are a variety of types to choose from.

Genetic Types of Sweet Corn

There are five main types of sweet corn available to home gardeners. These types vary in sugar content, texture, length of harvest period, storage life, and seed vigor/germination requirements. The five main types of sweet corn are standard sugary (su), sugary enhanced (se), shrunken-2 (sh2), synergistic (syn), and augmented supersweets (shA). To help in cultivar selection, the characteristics of the five types of sweet corn are described below.

Standard Sugary (su)

            Standard sugary cultivars have been grown for many years. These cultivars have the traditional sweet corn flavor and texture. Sugar levels are generally between 10 and 15 percent at harvest. Unfortunately, ears of sugary cultivars retain their high quality for only 1 or 2 days. Also, standard sweet corn cultivars don’t store well as sugars quickly convert to starch after harvest. Seeds germinate well at soil temperatures of 55 to 60°F.

Sugary Enhanced (se)

            Sugary enhanced cultivars contain the sugary enhancer (se) gene that produces ears with sweet, tender kernels. Sugar levels are slightly higher than standard sugary cultivars. The harvest and storage life of se types are slightly longer than standard sweet corn. Seeds germinate well at soil temperature of 55 to 60°F.

Shrunken-2 (sh2) or Supersweets

            These cultivars contain the shrunken-2 (sh2) gene. The common name is derived from the shrunken or wrinkled appearance of the dried kernels. Shrunken-2 cultivars have very high sugar levels. They also convert sugar to starch slowly allowing for a longer harvest period and storage life. The seedcoats on kernels are rather thick, giving the corn a firmer, crunchy texture. Soil temperatures need to be at least 60°F for optimal germination.

Synergistic (syn)

            Synergistic sweet corn cultivars possess su, se, and sh2 genes. Synergistic cultivars are sweet, creamy, and tender. They have an excellent storage life. Seeds germinate well at soil temperature of 55 to 60°F.

Augmented Supersweets (shA)

            Augmented supersweets are an improved type of shrunken sweet corn as they contain the se gene. They are sweet, tender, and have a long storage life. Soil temperatures should be at least 60°F for optimal germination.




Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Horticulture and Home Pest News, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on May 8, 2020. The information contained within may not be the most current and accurate depending on when it is accessed.