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When to Plant Radish in Ontario County, NY

Ontario County, New York Zone 6b May

What to do in May

Your garden in Ontario County, New York is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost April 29
Avg. first frost October 20
Soil temp (4") 60°F
Watering Low
Pest pressure Low
Daylight 14.5 hrs
  1. Pick radish

    If you can't use it all right away, check the food-preservation section of your planner.

Coming up in June — start thinking about
  • First harvests: radish

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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.

Ontario County, New York is in USDA Zone 6b. The average last spring frost is April 29 and the first fall frost is October 20, giving you a growing season of approximately 174 days.

At an elevation of 33 feet, Ontario County receives approximately 50 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Radish to ensure they mature before fall.

Ontario County, NY (Zone 6b) Moderate season
174 days
Last Spring Frost April 29
174 growing days
First Fall Frost October 20

Ontario County Soil Profile

Soil Type

Silt Loam

Soil pH

4.9-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (121 days to spare)
Transplant: Apr 26 🍅 Harvest: May 24 – Jun 14
Recommended (50%) ✓ Fits season (125 days to spare)
Transplant: Apr 29 🍅 Harvest: May 27 – Jun 17
Safe Start (90%) ✓ Fits season (124 days to spare)
Transplant: May 14 🍅 Harvest: Jun 11 – Jul 2

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.

Soil Compatibility in Ontario County

How your county's soil matches Radish's growing requirements.

Soil pH

Your soil pH (4.9–6.6) is more acidic than Radish prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Ontario County is excellent for Radish — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.0%). Annual compost additions will help Radish.

How to Plant Radish

0.5"
Planting Depth
2"
Between Plants
6"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Radish

9
successive plantings in your 174-day season

Sow every 2.4 weeks. Last sowing by Sep 15 to harvest before frost.

For a dedicated fall crop, sow by Aug 11.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Radish

Radish needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Radish Needs Rainfall You Supplement Action
Jan 3.3" 0" ❄️ Dormant
Feb 3.6" 0" ❄️ Dormant
Mar 3.9" 0" ❄️ Dormant
Apr 2.2" 3.8" 0" ✅ Rainfall sufficient
May 2.2" 4.8" 0" ✅ Rainfall sufficient
Jun 2.2" 5" 0" ✅ Rainfall sufficient
Jul 2.2" 4.7" 0" ✅ Rainfall sufficient
Aug 2.2" 4.4" 0" ✅ Rainfall sufficient
Sep 2.2" 4.4" 0" ✅ Rainfall sufficient
Oct 2.2" 4.1" 0" ✅ Rainfall sufficient
Nov 4.1" 0" ❄️ Dormant
Dec 4" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Ontario County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Radish Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Radish needs ~370 GDD — county provides 2,262 GDD Excellent fit

Radish Planting Timeline — Ontario County, NY

Radish Planting Calendar

Activity When Date Range
Direct Sow April 15 Apr 15 – May 6
Harvest May 13 May 13 – Jun 3
Fall Sowing August 11 Aug 11 – Aug 25

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

22–35 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 6b

📆 Growing Season

174 days in Ontario County

Growing Tips for Radish in Ontario County

Direct sow Radish outdoors after April 29 in Ontario County when soil has warmed and frost danger has passed.

Your generous 174.0-day season in Ontario County allows multiple plantings of Radish. Sow every 11.0 days for continuous harvest.

Common pests for Radish in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Radish in Ontario County, NY?

Ontario County is in Zone 6b with an average last frost of April 29. Plan your Radish planting based on this frost date — see the calendar above for exact timing.

What planting zone is Ontario County, NY?

Ontario County, New York is in USDA Hardiness Zone 6b. The average last spring frost is April 29 and first fall frost is October 20.

🌱

Your Ontario County Garden Planner — Free

A 24-page printable planner built for Ontario County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

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

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.