Cindy Haynes
Associate Professor
Department of Horticulture
Iowa State University
Article reprinted with permission from Horticulture and Home Pest News.
Popcorn is currently one of America's favorite snack foods. However, it has been cultivated for several thousand years. Popcorn is one of the oldest types of corn with some types dating back to 3600 BC. There are two types of popcorn, pearl and rice. Pearl types have smooth and rounded kernels, while rice types have more elongated kernels. In addition to the variation in kernel shape, popcorn varieties are available in red, pink, blue, yellow, and multi-colored ears.
Popcorn is grown for its tasty, exploding seed. Heating the kernel converts the moisture inside the kernel to steam and turns the seed inside out. The quality of the end product depends on the conditions during growing, harvest, and storage.
Growing
Several different varieties are available to home gardeners. Be sure to select a variety that will mature in your area. Sow seed directly in the garden in spring in several short rows. This ensures good pollination. Thin as recommended on label directions. Do not plant sweet corn in the same garden with popcorn. The quality of the sweet corn will be reduced if it is cross-pollinated by popcorn.
Water, fertilize, and weed regularly. Any serious stress like water deficiency can greatly reduce yields and the quality of the popcorn.
Harvest
Allow the kernels to dry in the field as long as possible. When harvested, the kernels should be hard and the husks completely dry.
After harvest, remove the husks and place the ears in mesh bags and hang in a warm, dry, well-ventilated location. The ideal moisture content for popcorn is between 13 and 14%. Once or twice a week, shell a few kernels and try popping them. When the test kernels are popping well and tasting good, shell and store the rest of the kernels. If the popcorn is "chewy" or the popped kernels are jagged, it is too wet and needs to continue drying.
Storage
Store the kernels in sealed, airtight containers. If stored properly, popcorn should retain its popping quality for several years. Unshelled corn should be stored at temperatures near 32F and high relative humidity. The storage location should also be rodent proof.
If stored popcorn fails to pop, it may be too dry. Add 1 tablespoon of water to a quart of popcorn. Cover and shake at frequent intervals until the popcorn has absorbed the water. After 3 or 4 days, test pop a few kernels to see if it is ready. Add more water and repeat the process until the popcorn pops well.
Below is a listing of a few varieties of popcorn that are readily available. Kernel color, height, maturity times, and source are included.
| Variety | Kernel Color | Height | Maturity Time | Source |
| Cutie Pops | Multi-colored | 6 feet | 100 days | Stokes Seed, Inc. |
| Mini Blue | Dark Blue | 6 feet | 100 days | Harris Seeds |
| Mini Pink | Pink - Purple | 6 feet | 105 days | Harris Seeds |
| Robust | Yellow | 8 feet | 112 days | Johnny's Select |
| Ruby Red | Dark Red | 8 feet | 110 days | Johnny's Select |
| Shaman's Blue | Purplish Blue | 7 feet | 112 days | Johnny's Select |
| Strawberry | Dark Red | 4 feet | 100 days | Stokes Seed, Inc. |
| Tom Thumb | Yellow | 3 feet | 85 days | Johnny's Select |
| Top Pop | Yellow | 6 feet | 100 days | Harris Seeds |