My father used to say that if you wanted to eat sweet corn while
it was still sweet, you had to get the water boiling before you
went to the garden. He was right. However, that axiom doesn’t
necessarily hold for modern sweet corn.

As we get ready to plant the spring crops, it’s a good time to
look at some alternative sweet corn varieties — ones that hold
their sweetness long after you’ve plucked them from the stalk.

The most popular of the garden and roadside market sweet corns
has long been “Silver Queen.” Yes, “Silver Queen” is a fine sweet
corn. Its sweet flavor comes on a long ear with full, tender
kernels.

Old Sweet Corn Favorites

When consumers go looking for sweet corn, then, Silver Queen is
often the variety they ask for. Other favorites over the years
have been “Trucker’s Favorite,” “Golden Cross Bantam,” “Seneca
Horizon” and “Merit.”

All of these old favorites are called standard sweet corn
varieties. They differ from field corn by one gene called the
sugary gene and are referred to with the abbreviation
“su.”

Although these varieties have good sugar content, the minute
they’re pulled from the stalk they begin converting their sugar
to starch. Therefore, the longer they’ve been picked, the less
sugar and more starch the kernels have.

Supersweet Corn

In the 1970s, a new type of sweet corn, referred to as supersweet
(sh²), was introduced.

Supersweet corn varieties contain two to four times more sugar
than the su types, and the gene causes the conversion from
sugar to starch to occur much slower. This allows them to retain
their sweet flavor much longer than su types.

Often, sh² corn has a fairly thick seed
coat that makes them tougher than su types. And they tend
to be more watery. They also have to be isolated from standard
varieties and don’t germinate well in cool soils.

Sugary Enhanced Corn

In 1980, varieties called sugary enhanced (se) were
introduced. These have higher sugar content than the su
varieties. However, the sugar still converts to starch at the
same rate.

Although they stay sweeter longer than su types, they
eventually lose their sweetness in the same way. These varieties
have tender seed coats, aren’t watery and germinate better in
cooler soils than sh² types.

More recently, even more varieties have been introduced with a
combination of these traits. Some have advantages of all three
types.

Latest Combinations

They’re sweeter and convert sugar to starch more slowly. Yet they
have a tender seed coat and are less watery, too. And they
germinate well in cooler, early-spring soils. On the surface,
these newer combinations would seem to be the ticket.

However, in many of the combination types, only 25 percent of the
kernels will be of the sweeter type. The so-called “synergistic”
types are like this. The “improved supersweet” types are actual
sh² types with su characteristics as
well.

So What’s Best?

So, how do you decide what to plant?

Well, the su and se types are not best for
shipping, but for garden and roadside sales they’re fine. The
improved sh² types hold sweetness while
otherwise being more like su and se types.

One caution: sh² types should be isolated
from su and se types or field corn. Otherwise,
they’ll cross-pollinate and cause the sh²
types to be more starchy.

Isolate these varieties from others by planting them 250 feet
apart or by planting so they’re 10 to 14 days apart in
maturity.

Otherwise, try some of these new corn types. You may be surprised
that you can wait until you get back to the house to start
boiling the water.