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When to Plant Corn in Todd County, SD

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.

Todd County, South Dakota is in USDA Zone 4b. The average last spring frost is May 6 and the first fall frost is October 6, giving you a growing season of approximately 153 days.

At an elevation of 1,071 feet, Todd County receives approximately 28 inches of rainfall annually with predominantly loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Corn to ensure they mature before fall.

Todd County, SD (Zone 4b) Moderate season
153 days
Last Spring Frost May 6
153 growing days
First Fall Frost October 6

Todd County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (38 days to spare)
Transplant: Apr 29 🍅 Harvest: Jul 1 – Aug 26
Recommended (50%) ✓ Fits season (34 days to spare)
Transplant: May 6 🍅 Harvest: Jul 8 – Sep 2
Safe Start (90%) ✓ Fits season (38 days to spare)
Transplant: May 19 🍅 Harvest: Jul 21 – Sep 15

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
0.8″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 868 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Corn needs ~980 GDD — county provides 1,874 GDD Excellent fit

Corn Planting Timeline โ€” Todd County, SD

Corn Planting Calendar

Activity When Date Range
Direct Sow May 20 May 20 โ€“ Jun 10
Harvest July 22 Jul 22 โ€“ Sep 16

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

153 days

Growing Tips for Todd 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

Level Up Your Garden

Frequently Asked Questions

When should I plant Corn in Todd County, SD?

Todd County is in Zone 4b with an average last frost of May 6. Plan your Corn planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Todd County, SD?

Todd County, South Dakota is in USDA Hardiness Zone 4b. The average last spring frost is May 6 and first fall frost is October 6.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Todd 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 Todd County, SD. Local conditions may vary. Last updated: April 2026.