Gardeners usually rush to harvest and eat fresh sweet corn as soon as it's ripe. However, there's another type of corn that can be harvested more casually. Popcorn is as easy to grow as sweet corn, but you don't have to be as diligent about harvesting it on time. While most gardeners think of the usual white or yellow popcorn varieties, there are others with unique characteristics that can add an interesting twist to movie night.
Popcorn is native to the Americas, with an ancient history dating back more than 5000 years. It's believed the first use of corn was for popping. Aztec Indians in the 16th century used popcorn in ceremonies as headdresses, necklaces, and for food. It was "toasted until it burst" to make it more edible. As soon as American farmers starting growing feed and sweet corn, they also grew popcorn.
Today, it's one of the most popular snack foods. The average American consumes more than 54 quarts of popcorn a year.
To grow popcorn all you need is a plot of land, fertile soil, and knowledge of when to harvest and how to store the seeds.
Popcorn is different from other types of corn because of its moisture content. Popcorn's kernels consist of nearly all hard starch covered by a thin, hard shell with moisture inside. Each kernel acts as a miniature steam engine when heated. As pressure builds and the moisture inside expands, the kernel explodes, and out comes the fluffy white kernels we love to eat.
Popcorn is available in a range of colors such as white, red, blue, and yellow. The best variety for you to grow depends mostly on your personal preference and the length of your growing season. In areas with short growing seasons, select varieties that mature quickly, such as the open-pollinated, white-kerneled 'Japanese Hulless'. This 4- to 5-foot-tall plant produces small, nearly hull-less popped kernels in about 85 days from sowing.
In all other areas, select popcorn varieties based on flavor and cob color. Yellow popcorn tends to pop into bigger kernels than white popcorn. A good yellow variety to try is the hybrid 'Robust 9035'. It produces 8-inch-long ears that pop to a light yellow color. 'Snow Puff' is a very tender hybrid white variety with thin hulls. For a corn of a different color, 'Shaman's Blue' is a blue hybrid that produces 8-inch-long ears with glossy blue hulls that pop into white kernels with black accents. It has a crunchy texture and savory flavor. The open-pollinated 'Red Strawberry' produces 2- to 4-inch-long, dark red ears that are attractive as ornamentals as well.
Like sweet corn, popcorn loves warm, well-drained, fertile soil; plenty of moisture and fertilizer during the growing season; and lots of sun. Most varieties require at least 100 days to mature. Unlike sweet corn, popcorn needs to mature fully on the stalk before harvesting. After danger of frost has passed, prepare the soil well and add compost. Popcorn seed germinates more slowly than sweet corn seed, and the root systems aren't as extensive, so give the plants more care by weeding, watering, and fertilizing regularly.
Plant in short blocks of four to six rows to insure adequate pollination. To avoid contamination from other corn types, don't plant sweet corn or other types of corn closer than 250 feet from the popcorn. After germination, fertilize the soil with a highly soluble nitrogen fertilizer, such as fish emulsion. Hill up the soil around the plants once the corn is 1 to 2 feet tall to help prevent the plants from blowing over in high winds. Each stalk will produce 1 to 2 ears. Six, 8-inch-long ears will yield 1 pound of popcorn.
Keep the plants well weeded and watered with at least 1 inch of water per week. Watch for the same insects and animals you would find feeding on sweet corn. (See Sweet Corn Solutions in the Food Garden Garden for more on corn pest control.)
Leave popcorn ears on the stalk until the husks are brown and dry. When you can no longer leave a mark on the kernel when you press it with your fingernail, it's time to harvest. Before the first frost, twist and snap each ear from the stalk. Carefully strip away the dried husk from each ear. The kernels will be partially dried or "cured" already, but they will need an additional few weeks of thorough drying. Place the ears in mesh bags and hang or spread them out to dry in a warm, well-ventilated place, such as a garage, for four to six weeks.
After curing, hang the bags of corn in a cool, dry place. The corn will keep for years in cool, dry, dark conditions. Or you can remove the kernels from the cobs and store them in an airtight glass or plastic container in a cool, dark location. Don't place the jars in the refrigerator or leave jars open on hot humid days. A change in moisture content can prevent the kernels from popping.
Whether you're removing the kernels before storage or just before popping, there's no real trick to it. Simply grasp an ear firmly in both hands and twist until the kernels drop out. If the kernels can be removed easily, they are probably close to the ideal 14 percent moisture content that promotes the best popping.
QUESTION OF THE WEEK
Q. I have about five watermelon fruits on my plant. I was wondering how tell when to harvest?
A. There are a few clues that indicate ripeness. Some gardeners like to give their watermelons a good thump. You'll need to experiment with this technique. If thumping produces a high pitch, the melon is unripe. A dull sound means it's either ripe or even overripe. Some gardeners determine watermelons are ripe when the stiff, curly tendril on the vine where the watermelon attaches has turned brown. Another indicator is when the pale bottom of the fruit is golden or deep yellow (as opposed to straw colored).