Popcorn (Zea mays everta) is a specific type of flint corn and a relatively simple crop for the home gardener. Its unique ability to explode into a fluffy snack is due to the small amount of water trapped within its hard hull. Successfully growing popcorn requires attention to soil, pollination, and the post-harvest drying process. Following the correct steps from planting to curing ensures a successful harvest of kernels that pop consistently.
Getting Started: Variety Selection and Soil Requirements
Choosing the correct variety is the first step, as kernels pop into distinct shapes: mushroom or butterfly popcorn. Butterfly popcorn is the familiar movie-theater type, characterized by irregular, airy pieces that hold butter and salt well, but it tends to crumble easily. Mushroom popcorn, by contrast, pops into a dense, compact, ball-shaped piece, making it the preferred choice for applying heavy coatings like caramel or chocolate, as its sturdy shape resists breaking.
Popcorn requires a full-sun location that receives at least six to eight hours of direct sunlight daily, as shade limits ear production. The soil should be well-drained and rich in organic matter, with a slightly acidic to neutral pH range of 5.8 to 7.0. Since corn is a “heavy feeder,” it benefits from incorporating compost or well-rotted manure before planting. This preparation helps amend heavy soils and encourages better root development.
Planting, Pollination, and Mid-Season Care
Popcorn seeds should be direct-sown only after the danger of the last frost has passed and the soil temperature has warmed to at least 60°F (70°F is better for optimal germination). Planting too early in cool soil can cause seeds to rot before they sprout. Corn does not transplant well, so starting seeds indoors is not recommended.
For successful kernel development, popcorn relies on wind for pollination. Therefore, it must be planted in a block or square arrangement rather than a single long row. Planting in at least four short rows ensures that pollen from the tassels falls onto the silks of the ears below, preventing blank spots on the cobs. Spacing seeds about one inch deep and eight to twelve inches apart, with rows 18 to 24 inches apart, provides the necessary density for good pollination.
Popcorn is a thirsty crop, requiring consistent moisture, especially during the tasseling and silking stages. A general guideline is to provide about one inch of water per week, soaking the soil thoroughly. As a heavy feeder, corn needs nitrogen fertilization, typically side-dressed when the plants are about a foot tall and again as they begin to tassel. Keeping the planting area weed-free prevents competition for water and nutrients, ensuring a strong final yield.
Harvesting, Drying, and Storing Your Crop
The harvesting and curing process is the most important aspect of growing popcorn, as it directly impacts the kernels’ ability to pop. Popcorn must be allowed to fully mature and dry on the stalk, a process that takes 90 to 120 days depending on the variety. The husks must turn completely brown and dry, and the kernels should feel hard and shiny before harvest. Many gardeners wait until after the first light frost to ensure maximum drying.
After harvesting, the ears must be shucked and moved to a dry, well-ventilated location to cure for several weeks or months. This curing phase reduces the kernel’s moisture content to the ideal range of 13.5% to 14%. If the moisture level is too high, the popped corn will be small and chewy; if it is too low, the kernels will not pop effectively.
Since most home gardeners do not have a moisture meter, the best method for testing readiness is the “test pop.” After the ears have dried for a month or more, shell a small handful of kernels and attempt to pop them. If the majority of kernels pop fully and fluffily, the crop is ready; if the pops are small or sparse, the corn needs another week or two of drying time. Once cured and popping well, shell the kernels from the cob and store them in an airtight container in a cool, dark place to maintain the perfect moisture level.