Quick planting window
| Start indoors | Not recommended; sow seeds directly instead |
|---|---|
| Transplant | Not recommended; sow seeds directly to avoid root disturbance |
| Sow seeds | June to July |
| Estimated harvest | August to September |
| Risk | Medium risk |
Month calendar
Scan the year by month to see seed starting, sowing, transplanting, and harvest timing.
Corn is frost sensitive. Wait until the conservative transplant or sowing window for Colorado.
Next: ZIP code personalization
This is a state-level planning window based on typical frost timing and crop rules. Use local Extension guidance or a ZIP code frost-date tool before planting.
Planning notes
Days to maturity
80
Covered states
Colorado
Frost window
May to June / September to October
Front Range, mountain, and western slope gardens can have very different timing.
Corn growing notes
The calendar window is only the first step. These growing details affect survival, plant vigor, and harvest quality.
Sun
Full sun.
Soil
Fertile soil with steady nitrogen and moisture.
Spacing
8-12 inches in short blocks, not one long row.
Container
Not ideal for small containers.
Watering
Needs consistent water during tasseling and ear fill.
Common mistake
Planting too few plants for good pollination.
Beginner tip
Plant in blocks of several short rows.
Month window table
| Crop | Spring transplant / sow | Spring harvest | Fall transplant / sow | Fall harvest |
|---|---|---|---|---|
| Corn | June to July | August to September | July to August | September to October |
Sources and limits
This page uses Colorado state-level frost windows, USDA zone ranges, and crop rules for planning. It does not replace local Extension or county-level guidance.
FAQ
When should I start corn seeds indoors in Colorado?
Corn is usually not started indoors. Sow outdoors in the recommended window instead.
When should I transplant corn in Colorado?
Corn is usually better sown outdoors because transplanting can disturb the roots.
Can I sow corn outdoors in Colorado?
Yes. The spring outdoor sowing window is about June to July, assuming soil and night temperatures are suitable.
When can I harvest corn in Colorado?
Spring planting estimates a harvest around August to September; fall planting estimates about September to October. Variety and weather can shift this by several weeks.
Is corn risky in Colorado?
Corn is frost sensitive. Wait until the conservative transplant or sowing window for Colorado. For fall: Corn is frost sensitive. Fall planting in Colorado needs enough warm days before first frost.
Do local differences inside Colorado matter?
Front Range, mountain, and western slope gardens can have very different timing. Treat this as a state-level starter window and confirm with a local Extension or frost-date tool before planting.
What growing details matter most for corn?
Full sun. Fertile soil with steady nitrogen and moisture. Common mistake: Planting too few plants for good pollination.
Is this ZIP-code accurate?
No. This page uses state-level windows; ZIP-code frost dates, USDA zone matching, and reminder calendars are planned for the next phase.