How to pick a sweet corn variety
Choosing a sweet corn variety for your garden can be confusing. They all taste good with butter and salt come summer, but are there differences?
There are three major types of sweet corn, says Richard Jauron, Extension horticulturist, Iowa State University: standard, supersweet, and sugar-enhanced.
There is also a new type of sweet corn that combines the characteristics of supersweet and sugar-enhanced. It is called synergistic sweet corn. All types differ in sweetness, keeping quality, and seed vigor.
Standard varieties
Standard varieties possess the traditional sweet corn flavor and texture. Unfortunately, the ears of standard sweet corn varieties retain their quality for only one or two days in the garden. Also, standard sweet corn varieties don't store well as the sugar is quickly converted to starch.
Supersweet varieties
Supersweet or shrunken-2 sweet corn contains up to twice the amount of sugar as standard varieties. (The common name shrunken-2 is derived from the shrunken or wrinkled appearance of the dry kernels.) Also, the conversion of sugar to starch occurs at a much slower rate. As a result, supersweet varieties may be harvested and stored over a longer time period.
However, yields of supersweet varieties are generally lower than standard sweet corn. Also, the seeds of shrunken-2 varieties are smaller than standard sweet corn varieties and germinate poorly in cold soils. While standard sweet corn can be planted in late April in central Iowa, for example, supersweet varieties should not be planted until mid-May.
Sugar-enhanced varieties
The sugar levels of sugar-enhanced sweet corn are between those of standard and supersweet varieties. The soft kernels make this corn tender and easy to chew. The harvest and storage periods are slightly longer than standard sweet corn. Plant one week later than standard varieties.
Synergistic varieties
The newest type, synergistic sweet corn, has higher levels of sugar than sugar-enhanced and more tender kernels than supersweet varieties. Synergistic varieties should be planted later than standard varieties as their seeds germinate poorly in cold soils.
