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When to Plant Corn in Jefferson County, NY

Corn is a warm-season grass grown for its sweet ears, which are best eaten soon after harvest. It is wind-pollinated and must be planted in blocks for good kernel fill.

Jefferson County, New York is in USDA Zone 4b. The average last spring frost is May 10 and the first fall frost is October 6, giving you a growing season of approximately 149 days.

At an elevation of 468 feet, Jefferson County receives approximately 39.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85ยฐF, providing good warmth for Corn during the growing season.

Jefferson County, NY (Zone 4b) Short season
149 days
Last Spring Frost May 10
149 growing days
First Fall Frost October 6

Jefferson County Soil Profile

Soil Type

Silt Loam

Soil pH

4.9-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (35 days to spare)
Transplant: May 1 🍅 Harvest: Jul 3 – Aug 28
Recommended (50%) ✓ Fits season (30 days to spare)
Transplant: May 10 🍅 Harvest: Jul 12 – Sep 6
Safe Start (90%) ✓ Fits season (31 days to spare)
Transplant: May 23 🍅 Harvest: Jul 25 – Sep 19

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Corn needs ~1,100 GDD — county provides 2,048 GDD Excellent fit

Corn Planting Timeline โ€” Jefferson County, NY

Corn Planting Calendar

Activity When Date Range
Direct Sow May 24 May 24 โ€“ Jun 14
Harvest July 26 Jul 26 โ€“ Sep 20

Plant 1" deep ยท 12" apart ยท Rows 36" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May Direct Sow
June Direct Sow
July Harvest
August Harvest
September Harvest
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

60โ€“100 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 4b

Growing Season

149 days

Growing Tips for Jefferson County

Plant in blocks of at least 4 rows rather than single rows for proper pollination. Direct sow after soil reaches 60F. Side-dress with nitrogen when plants are knee-high.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Celery

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Frequently Asked Questions

When should I plant Corn in Jefferson County, NY?

Jefferson County is in Zone 4b with an average last frost of May 10. Plan your Corn planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Jefferson County, NY?

Jefferson County, New York is in USDA Hardiness Zone 4b. The average last spring frost is May 10 and first fall frost is October 6.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Jefferson County gardeners in Zone 4b organize planting dates, track what's growing, and never miss a planting window.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Jefferson County, NY. Local conditions may vary. Last updated: April 2026.