Sweet Corn
Dates below are counted from the average last spring frost or the average first fall frost. Enter a ZIP in the calendar for NOAA 1991–2020 station averages, or pick a zone and use the zone table.
When to plant
Soil and site
The heaviest nitrogen feeder in the garden — rich soil, side-dress when knee-high.
Seedlings
Direct sow in warm soil; cold ground gives patchy stands.
In the garden
Plant in blocks of at least 4 short rows, never one long row — corn is wind-pollinated and needs neighbors on all sides for full ears.
Picking
When silks are brown and dry, pierce a kernel: milky juice means ready. Roughly 20 days after silks first appear.
Harvest
First harvest is about 65–90 days after sowing or planting outdoors. The picking window often runs about 1 week.
Silks are brown and dry, and a pierced kernel gives milky juice. That is usually about 20 days after silks first show.
Preserving
Sweet corn is low-acid. Do not can it in a boiling-water canner. Cream-style corn is a separate tested method from whole kernel.
USDA's tested method for whole-kernel sweet corn is pressure canning. Use the linked tables rather than a boiling-water canner.
National Center for Home Food Preservation: Corn, whole kernel →Freeze corn on the cob or as cut kernels with the NCHFP method.
National Center for Home Food Preservation: Freezing corn →Dry cut kernels with the NCHFP drying guide, then condition them before storage.
National Center for Home Food Preservation: Drying fruits and vegetables →A home freeze-dryer can dry this crop, but USDA has not published a canning-style time for it. Follow the appliance manual for load and cycle length, then store the dry food sealed. Freeze-drying is not a substitute for a tested canning process.
Appliance manual (no USDA process time)
Canning, pickling, and fermenting notes here are summaries of tested USDA and National Center for Home Food Preservation methods. Times, pressures, and amounts live only on those pages. This site does not publish home-invented processing times.
Gear placeholders
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- Placeholder: seeds for Sweet Corn
- Placeholder: canning gear
- Placeholder: home freeze dryer
Dates by zone
These pages turn the same frost offsets into calendar dates for each zone the calendar covers.