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When to Plant Peppers in Union County, SD

Sweet peppers are warm-season crops producing fruits in a rainbow of colors. They turn from green to red, yellow, or orange as they ripen, increasing in sweetness.

Union County, South Dakota is in USDA Zone 5a. The average last spring frost is April 30 and the first fall frost is October 5, giving you a growing season of approximately 158 days.

At an elevation of 938 feet, Union County receives approximately 22.8 inches of rainfall annually with predominantly loam soil. Summer highs average 86ยฐF, providing good warmth for Peppers during the growing season.

Union County, SD (Zone 5a) Moderate season
158 days
Last Spring Frost April 30
158 growing days
First Fall Frost October 5

Union County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (13 days to spare)
Start indoors: Feb 12 Transplant: May 7 🍅 Harvest: Jul 9 – Sep 17
Recommended (50%) ✓ Fits season (11 days to spare)
Start indoors: Feb 19 Transplant: May 14 🍅 Harvest: Jul 16 – Sep 24
Safe Start (90%) ✓ Fits season (6 days to spare)
Start indoors: Mar 6 Transplant: May 29 🍅 Harvest: Jul 31 – Oct 9

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
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 665 gal / 100 sq ft
Drought risk

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

Peppers needs ~1,088 GDD — county provides 2,291 GDD Excellent fit

Peppers Planting Timeline โ€” Union County, SD

Peppers Planting Calendar

Activity When Date Range
Start Indoors February 19 Feb 19 โ€“ Mar 5
Transplant Outdoors May 14 May 14 โ€“ May 28
Direct Sow May 7 May 7 โ€“ May 28
Harvest July 16 Jul 16 โ€“ Sep 24

Plant 1" deep ยท 15" apart ยท Rows 24" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March Start Indoors
April โ€”
May Transplant Outdoors Direct Sow
June โ€”
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€“90 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 5a

Growing Season

158 days

Growing Tips for Union County

Start seeds indoors 8-10 weeks before last frost. Transplant when nighttime temperatures stay above 55F. Avoid high-nitrogen fertilizers which promote leaves over fruit.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel
  • Kohlrabi

Level Up Your Garden

๐ŸŒพ Save Your Own Peppers Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Remove seeds from fully ripe (red/orange) fruit.
Storage Store airtight; viable 4 years at 35ยฐF, under 50% humidity.

Isolate 300 ft for purity. Hot and sweet peppers can cross-pollinate.

Frequently Asked Questions

When should I plant Peppers in Union County, SD?

Union County is in Zone 5a with an average last frost of April 30. Plan your Peppers planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Union County, SD?

Union County, South Dakota is in USDA Hardiness Zone 5a. The average last spring frost is April 30 and first fall frost is October 5.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Union County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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