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Herbs, Flowers & Specialty CropsPopcorn Planting Calendar
Popcorn grows like other corn but fails in unique ways: cross-pollination, harvest moisture and storage all change how well it pops. A calendar for it follows warm soil, isolation and slow drying.
Key points
- Plant after frost danger in warm soil, using a soil thermometer.
- Isolate popcorn from other corn by distance or planting date.
- Follow your soil test and extension guidance for fertility.
- Dry and store to the recommended moisture for good popping.
When should you plant popcorn?
Popcorn is a warm-season grass and is planted after the last spring frost, when soil has warmed. For field corn, land-grant extension and the USDA NASS Usual Planting and Harvesting Dates publication describe typical planting windows by state. Popcorn is not a standard NASS category, but the general corn season is a useful guide.
Use a soil thermometer. Corn seed planted into cold, wet soil is slow to emerge and prone to rot. If cold weather is forecast after planting, ask your extension office whether replanting is likely to be needed.
If an early planting is hit by frost, young corn often recovers because the growing point is below ground in the early stages. Check plants a few days after the cold before deciding to replant, and ask extension for guidance.
How far should popcorn be from other corn?
Corn is wind pollinated, so pollen from sweet corn, field corn or ornamental corn can cross with popcorn and reduce popping quality. Extension and seed-saving sources recommend isolation by distance or by staggering planting dates so silking does not overlap. Distances and timing differences are given in local guidance, so use those for your area.
Remember that neighbors' fields count. Ask nearby farmers what they are planting.
Test your popcorn before you store all of it. After drying, pop a small sample and note the proportion that pops and the quality of the result. If results are poor, adjust the moisture by further drying or by rehydration methods suggested by your extension office or seed supplier. A simple test each year shows whether your harvest timing and storage are working and gives you data for next season's calendar.
How do you prepare soil and manage fertility?
Corn is a heavy feeder. Take a soil test and follow your extension service's recommendations rather than a generic rate. Good drainage and a weed-free seedbed matter, and crop rotation helps with pest and disease control. Nutrient management rules vary by state, including any limits on manure timing.
Plant in blocks of several short rows rather than one long row, since blocks improve pollination. Good seed contact with moist soil improves emergence, and planting depth guidance comes from your seed supplier and extension.
What does the growing season involve?
After planting, the main tasks are weed control, water during dry spells and scouting for pests. Pollination happens when silks emerge, and heat or drought at that time can reduce kernel set. Keep notes on silking date, weather and any problems.
Herbicides, insecticides and fungicides must be used strictly according to the label, and not all products are labeled for popcorn. Ask your extension office.
- Early: control weeds while plants are small.
- Silking: keep water available if rainfall is short.
- Late: scout ears for insects and disease.
When is popcorn ready to harvest?
Popcorn is left in the field until kernels are hard and the husks dry, which allows moisture to fall naturally. Harvest moisture strongly affects popping, and extension sources describe a target moisture range for storage and popping. Use a grain moisture tester or ask your extension office how to check.
Wet weather or early frost can delay drying, so plan for extra time in a cool fall.
Keep a note of the weather around silking and the harvest dates. Popcorn quality varies from year to year, and your notes help you separate weather effects from variety or handling effects.
How do you dry and store popcorn?
After harvest, continue drying ears in a well-ventilated, rodent-resistant space until kernels reach the recommended moisture, then shell and store in airtight containers. Too dry and kernels fail to pop fully; too wet and they pop poorly or mold. Check stored popcorn periodically. For home food storage questions, use guidance from the National Center for Home Food Preservation and your extension office.
What problems are common?
Poor popping from cross-pollination or wrong moisture, ear worms and ear mold, and lodging in wind are among the usual problems. If you sell popcorn, check state rules on labeling and food handling with your state department of agriculture.
Popcorn is a crop where small details decide the result. Isolation, harvest moisture and storage all matter, and none shows its effect until the kernels hit the pan. Record each step in a notebook so that a good batch can be repeated and a poor one explained.
Sources and further reading
Last reviewed: November 2026. Educational information, ranges only. Confirm timing with your county extension office.