News release: Popcorn

Tim Baker, MU Extension Horticulture Specialist
102 N. Main, Suite 1, Gallatin, MO 64640
660-663-3232, bakert@missouri.edu

Release Date: May 11, 2017
Headline: Popcorn

Some gardeners are natural experimenters, always looking for a new crop to try.  After a while, tomatoes, green beans and sweet corn become passé, so they start looking from something else to add to their garden.  If you fall into the above category and are looking for something a little different to try, you might consider sweet corn’s close relative, popcorn.

Popcorn is a type of corn that has a high proportion of hard starch.  When you heat it, the moisture in the starch grains expands, and the kernel explodes.  Proper moisture content is critical to good popping quality, so good growing and storage conditions are needed for the best results.

There are two types of popcorn classifications: rice corns and pearl corns.  Rice corns have more sharply pointed kernels, while pearl corns have a smooth, more rounded shape.

Popcorn comes in several colors.  All turn white upon popping.  Most typical are the white and yellow popcorn.  But other colors which you may see in seed catalogs include red and black.  Some of the colored varieties are sold for decorative purposes, such as strawberry popcorn, which produces a small ear. Culture for popcorn is similar to sweet corn. 

Can you grow sweet corn and popcorn in the same garden?  Yes, you can, but be aware that the two types of corn cross-pollinate.  With most vegetables, cross-pollination is not a problem, unless you are saving seed.  With corn, however, the pollen from the popcorn (or other types of corn) may cause your sweet corn to be less sweet. If you want to grow both types of corn in the same year, the easiest way to deal with this problem is to plant several weeks apart, so that when the  pollen is released from the first planting, the second planting is not yet ready to be pollinated.

Both popcorn and sweet corn should be planted in blocks of several short rows parallel to each other, instead of one long row.  This is to insure good pollination, and well-filled ears.  The site should be sunny, with well-drained soil.

Popcorn will take longer to grow than sweet corn, since you are growing the plant to maturity.  Early to mid-May is the best time to plant.  A general-purpose garden fertilizer will get the plants off to a good start.  Side dressings are encouraged when the plants are about 10 inches tall, and later when the tassels appear.  Plant about 6 to 9 inches apart in the row, with about 2.5 to 3 feet between the rows.

Be sure to give the growing plants plenty of water, especially when the silk appears and the kernels start developing.  Keep weed competition to a minimum.  Diseases and insects should be monitored, and are similar to what is seen in sweet corn or field corn.

Leave the ears on the plant until maturity.  This will be after the stalks turn brown and dry out completely.  At this point the husks will be dry, and the kernels hard. 

To store, pull back the husks, or remove them completely.  Place the ears in mesh bags, and hang them in a warm, dry, well-ventilated area for several weeks.  After this you may shell the kernels, and place them in tightly-closed glass jars.  Then place the jars in the refrigerator for long-term storage.