Sweet corn and field corn, what are the differences?

Michigan’s cornfields currently abound. Here’s a brief explanation to help explain what kinds of corn are in the farm fields around you.

Driving along Michigan’s byways and back roads, you will see many fields of what’s commonly known as field corn growing. In late-July or early-August, there is an abundance of local sweet corn at farmers markets, farm stands and local stores. What is the difference between these two types of corn? The sweet corn that we enjoy at our summer picnics is similar, but is selected for different traits than field corn. Field corn is used to create a number of other food products including corn meal, corn chips and livestock feeds as well as a host of non-food products including ethanol and polymers that are used to create plastics and fabric.

In 2011, Michigan produced more than 89.3 million pounds of sweet corn for the vegetable market. According to the Corn Marketing Program of Michigan, in 2012, Michigan farmers produced 317.9 million bushels of corn for grain – the 11th largest harvest by state in the United States. Both kinds of corn are valuable in different ways but each is harvested at different times to maximize their value.

Sweet corn does not grow as tall as field corn and has leaves that are thinner. In Michigan, sweet corn is harvested in July through October when the silk at the top of the green ear turns brown. After harvesting, the sugars in corn begin to convert into starches which affects flavor. The fresher the corn, the more sweet it will taste. For more information about how to preserve corn, consult the Sweet Corn fact sheet from Michigan Fresh, a publication of Michigan State University Extension.

Corn that is grown for grain has taller stalks with larger thicker leaves than sweet corn. Field corn, also sometimes called “cow corn,” stays in the fields until the ears dry because corn is very high in moisture and must be dry to be processed. That is why farmers leave stalks in the field until they are golden brown in the fall. Once corn is dry in the field, it is harvested using a combine harvester. This machine will collect the whole corn plant – stalk, cob and all – and remove the kernels of corn from the cob leaving the rest in the field to provide fertilizer to the field, feed for animals or ground cover. The kernels are then sold to grain elevators and become part of the global commodity food system or a product for a non-food user of corn. Some of that corn is saved to provide seed for the next season’s corn crop.

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