Popcorn is a specific variant of maize which is the only corn type capable of popping. It belongs to the flint corn family, distinguished by its small, hard, and dense kernels that possess a unique structure. When the kernel is heated, the internal water turns to steam, building up extreme pressure until the hull abruptly ruptures, causing the starchy material to instantly expand into the familiar fluffy snack. Growing this corn is similar to cultivating field corn, but the critical post-harvest processes of drying and curing determine the quality of the final pop.
Selecting Your Popcorn Variety and Site Preparation
Choosing the right seed is the first step, as popcorn varieties differ primarily in the shape they take when popped. The two major types are “butterfly,” which is the classic, irregularly shaped popcorn with delicate wings, and “mushroom,” which pops into a dense, compact, and ball-like shape. Mushroom varieties are sturdier and better for coating with caramel or cheese, while butterfly is generally preferred for simple butter and salt applications due to its lighter texture. Popcorn also comes in various colors, such as white, yellow, red, and blue, though the popped color will always be white or off-white.
Corn is a wind-pollinated crop, making site preparation and planting layout a major consideration for a successful harvest. To ensure every silk receives pollen, you must plant in full sun in a block formation rather than a single long row. A minimum of four rows, spaced closely together, is recommended to maximize the chance that pollen released from the tassels will fall onto the silks below. The planting area should also consist of well-draining soil that is rich in organic matter to support the plant’s long growing season.
Planting and Essential Maintenance
Popcorn seeds should be direct-sown into the garden after all danger of frost has passed, specifically when the soil temperature is consistently 60°F or warmer. Plant seeds about one inch deep and thin the seedlings to stand approximately 8 to 12 inches apart within the rows. The block planting method ensures that the wind effectively carries the pollen from the male tassels at the top of the plant down to the female silks emerging from the developing ears.
A consistent water supply is particularly important once the plants reach their reproductive stage. Water stress during this silking period can desiccate the silks, preventing complete pollination and resulting in ears with missing kernels. Corn requires a high amount of water, which should be delivered through deep, infrequent watering to encourage strong root growth. Common garden pests, such as the corn earworm, feed on the silks and kernels, while diseases like corn smut can be managed by removing and destroying any infected galls before they release spores.
Knowing When and How to Harvest
Unlike sweet corn, which is picked when the kernels are soft and milky, popcorn must be left on the stalk until the plant is completely dead and dried out. This extended field time allows the kernels to fully mature and the moisture content to begin naturally dropping. The stalks will turn brown, the husks will become dry and brittle, and the kernels themselves will feel hard and glossy, typically occurring in late fall before a heavy, sustained frost.
After picking the ears, the initial drying phase requires placing the un-shelled ears in a protected, warm, and well-ventilated location, such as a shed or covered porch. Ears should be stored on the cob for several weeks to allow the moisture content to drop significantly. This initial drying is separate from the final curing, which fine-tunes the moisture level necessary for a good pop.
Curing, Shelling, and Testing the Pop
The true secret to quality homegrown popcorn lies in curing, which is the process of achieving an optimal moisture content of 13.5% to 14%. If the kernels are too wet, the resulting popped corn will be small, dense, and chewy, while if they are too dry, they will fail to pop or produce small, non-fluffy pieces called “old maids.” To cure, place the dried ears in a mesh bag or hang them in a warm, low-humidity area for four to six weeks, allowing the moisture to equalize.
You can begin shelling the kernels from the cob. The readiness of the kernels must be confirmed with a test pop, where a small handful is heated. If the test pop is unsatisfactory, the kernels can be adjusted; if they are too dry, a tablespoon of water can be added to a quart jar of kernels to rehydrate them. Properly cured kernels should be stored in an airtight container, such as a glass jar, to maintain the correct moisture level for up to several years.