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When to Plant Radish in Fremont County, WY

Radishes are one of the fastest-growing vegetables, with some varieties ready in under a month. They come in round, elongated, and large winter types.

Fremont County, Wyoming is in USDA Zone 4a. The average last spring frost is May 15 and the first fall frost is September 21, giving you a growing season of approximately 129 days.

At an elevation of 6,059 feet, Fremont County receives approximately 14.8 inches of rainfall annually with predominantly loam soil. Summer highs average 80ยฐF, so choose short-season varieties of Radish to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Radish successfully. Mulch heavily to conserve soil moisture.

Fremont County, WY (Zone 4a) Short season
129 days
Last Spring Frost May 15
129 growing days
First Fall Frost September 21

Fremont County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (80 days to spare)
Transplant: May 11 🍅 Harvest: Jun 8 – Jun 29
Recommended (50%) ✓ Fits season (80 days to spare)
Transplant: May 15 🍅 Harvest: Jun 12 – Jul 3
Safe Start (90%) ✓ Fits season (71 days to spare)
Transplant: Jun 10 🍅 Harvest: Jul 8 – Jul 29

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
0.5″/week
You supply
1.0″/week
Watering frequency 2-3 times/week
Season total 1,127 gal / 100 sq ft
Drought risk

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

Radish needs ~285 GDD — county provides 1,290 GDD Excellent fit

Radish Planting Timeline โ€” Fremont County, WY

Radish Planting Calendar

Activity When Date Range
Direct Sow May 8 May 8 โ€“ May 29
Fall Sowing June 29 Jun 29 โ€“ Jul 13
Harvest June 5 Jun 5 โ€“ Jun 26

Plant 0.5" deep ยท 2" apart ยท Rows 6" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

22โ€“35 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 4a

Growing Season

129 days

Growing Tips for Fremont County

Direct sow every 1-2 weeks for continuous harvest. Do not transplant. Harvest spring radishes promptly to prevent them from becoming pithy and hot.

Companion Planting

Good Companions

Avoid Planting Near

  • Hyssop

Level Up Your Garden

Frequently Asked Questions

When should I plant Radish in Fremont County, WY?

Fremont County is in Zone 4a with an average last frost of May 15. Plan your Radish planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Fremont County, WY?

Fremont County, Wyoming is in USDA Hardiness Zone 4a. The average last spring frost is May 15 and first fall frost is September 21.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Fremont County gardeners in Zone 4a 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 Fremont County, WY. Local conditions may vary. Last updated: April 2026.