Sweet corn
What Plant Yet? knows about sweet corn, and where each number comes from. For today's answer, pick your town.
Planting numbers
- Frost category
- Tender Source: Colorado State University Extension
- Plant outdoors
- On the typical last frost date Given for tender crops as a group. Source: Colorado State University Extension
- Cover at or below
- 32°F Given for tender crops as a group. Source: Utah State University Extension
- Grows once daytime temperatures reach
- 55°F Given for tender crops as a group. Source: Colorado State University Extension
- Days to harvest
- 60–90 Source: Utah State University Extension
Left out because we found no university extension source for it: minimum night temperature. We don't estimate.
Growing tips
- Plant in blocks at least three rows wide so wind can pollinate the ears. (Colorado State University Extension)
- For super-sweet (sh) types, wait until soil reaches 70°F in June. (Colorado State University Extension)
- Keep corn watered; drought delays silking and leaves ears with missing kernels. (Colorado State University Extension)
- Side-dress with nitrogen every three to four weeks through summer. (Colorado State University Extension)
- For a steady supply, stagger varieties or sow a second planting 20-30 days later. (Colorado State University Extension)
How the answer uses this
The planting window opens on the typical last frost date in your town and stays open while a planting still has 90 days to mature before the typical first fall frost. Inside the window the answer is Plant when the coldest of the next 7 nights stays above 32°F (no source gives a minimum night temperature, so the cold-damage temperature is used). Cover tonight shows when tonight's low is 32°F or colder while sweet corn is normally in the ground.
Sources
- Colorado State University Extension — checked Nov 11, 2026
- Utah State University Extension — checked Nov 11, 2026
- Utah State University Extension — checked Nov 11, 2026
- Colorado State University Extension — checked Nov 11, 2026
- Colorado State University Extension — checked Nov 11, 2026
Guidance only. Extension advice is written for typical conditions; your soil, variety and microclimate matter.