Blog

When to Plant Radish in Tompkins County, NY

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.

Tompkins County, New York is in USDA Zone 5b. The average last spring frost is May 10 and the first fall frost is October 11, giving you a growing season of approximately 154 days.

At an elevation of 309 feet, Tompkins County receives approximately 40.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87ยฐF, providing good warmth for Radish during the growing season.

Tompkins County, NY (Zone 5b) Moderate season
154 days
Last Spring Frost May 10
154 growing days
First Fall Frost October 11

Tompkins County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (107 days to spare)
Transplant: May 1 🍅 Harvest: May 29 – Jun 19
Recommended (50%) ✓ Fits season (105 days to spare)
Transplant: May 10 🍅 Harvest: Jun 7 – Jun 28
Safe Start (90%) ✓ Fits season (113 days to spare)
Transplant: May 21 🍅 Harvest: Jun 18 – Jul 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
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Radish needs ~435 GDD — county provides 2,348 GDD Excellent fit

Radish Planting Timeline โ€” Tompkins County, NY

Radish Planting Calendar

Activity When Date Range
Direct Sow April 26 Apr 26 โ€“ May 17
Fall Sowing August 2 Aug 2 โ€“ Aug 16
Harvest May 24 May 24 โ€“ Jun 14

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Direct Sow
May Direct Sow Harvest
June Harvest
July โ€”
August Fall Sowing
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 5b

Growing Season

154 days

Growing Tips for Tompkins 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 Tompkins County, NY?

Tompkins County is in Zone 5b with an average last frost of May 10. Plan your Radish planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Tompkins County, NY?

Tompkins County, New York is in USDA Hardiness Zone 5b. The average last spring frost is May 10 and first fall frost is October 11.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Tompkins County gardeners in Zone 5b 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 Tompkins County, NY. Local conditions may vary. Last updated: April 2026.