Types of sweet corn and how to harvest it properly

Corn is a new world crop. It was grown for thousands of years by Native Americans, but was unheard of in the old world, despite what the Bible says. Sweet corn is a relatively recent development, first documented in the 1770s in Pennsylvania. In the 1820s sweet corn seed began to show up in seed catalogs. Over the past two centuries, there has been significant improvement in sweet corn.

There are three genes that are responsible for corn sweetness: standard sugary (su), sugary extender (se), and supersweet (sh2).

su

The standard sweet gene is the original sweet corn gene. They are sweet and creamy, and should be harvested and eaten as soon as they are ripe, as the sugar in the kernel will rapidly convert to starch—in a few hours the flavor will be less sweet.

Common cultivars:

Yellow

• Earlivee
• Early sunglow
• Jubilee
• Merit
• Sundance

White

• Silver Queen
• True Platinum

Bicolor

• Butter & Sugar
• Honey & Cream
• Sweet G-90

se

Sugar extender sweet corn retains its sweetness a couple of days longer in the field and after harvest than su corn (2 – 4 days in refrigeration). The seed coat is thinner, making se corn tender and easy to chew.

Common cultivars:

Yellow

• Bodacious
• Buttergold
• Incredible
• Miracle
• Kandy Korn
• Precocious
• Sugar Buns

White

• Cloud Nine
• Platinum Lady
• Snowbelle
• Sugar Pearl

Bicolor

• Ambrosia
• Calico Belle
• Peaches and Cream
• Silver N Gold
• Sugar Baby

sh2

Supersweets have very high levels of sugar, which converts to starch very slowly. They hold their sweetness in the field and after harvest for several days, giving rise to a longer harvest and storage window. The seed coats are rather thick, giving the kernels a crisp texture. Sh2 corn requires warmer soils for germination.

Common cultivars:

Yellow

• Extra Early Super Sweet
• Jubilee SuperSweet
• Krispy King
• Summer Sweet Yellow

White

• Camelot
• Summer Sweet White

Bicolor

• Aloha
• Honey ‘N Pearl
• Summer Sweet Bicolor

Synergistic (sy)

Synergistic cultivars (often referred to as triple sweet cultivars) are those that combine the above genetics in different combinations. The percentage of su/se/sh2 kernels varies with each cultivar. While sy sweet corn does not need to be separated from other sweet corn genotypes, it is recommended, as cross pollination will affect the percentages of different sweet kernels.

Common cultivars:

Yellow

• Applause
• Honey Select
• Honeytreat
• Inferno

White

• Avalon
• Illusion

Bicolor

• Cameo
• Charisma
• Kristine
• Pay dirt
• Serendipity/Providence
• Sweetness
• Synergy

There are many more cultivars of the different sweet corn genotypes, and new cultivars are being developed every year.

Make sure there isn’t another cultivar close by (a minimum of 250 feet, in windy areas (think eastern Idaho) 700 feet supposedly gives complete isolation). This is especially true with field corn or popcorn in the vicinity. They can also be separated by time (at least two weeks between tasseling dates).

If you don’t already have your favorite corn selected, you might want to consider the types of sweet corn in your selection process.