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When to Plant Radish in Oakland County, MI

Oakland County, Michigan Zone 6a May

May in Oakland County, Michigan — your action list

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Oakland County, Michigan.

Avg. last frost April 28
Avg. first frost October 20
Soil temp (4") 61°F
Watering Low
Pest pressure Low
Daylight 14.4 hrs
  1. It's harvest week for radish

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

Looking ahead to June
  • 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.

Oakland County, Michigan is in USDA Zone 6a. The average last spring frost is April 28 and the first fall frost is October 20, giving you a growing season of approximately 175 days.

At an elevation of 1,286 feet, Oakland County receives approximately 39.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Radish during the growing season.

Oakland County, MI (Zone 6a) Moderate season
175 days
Last Spring Frost April 28
175 growing days
First Fall Frost October 20

Oakland County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-7.1

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 (126 days to spare)
Transplant: Apr 28 🍅 Harvest: May 26 – Jun 16
Safe Start (90%) ✓ Fits season (122 days to spare)
Transplant: May 13 🍅 Harvest: Jun 10 – Jul 1

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 Oakland County

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

Soil pH

Your soil pH (5.9–7.1) overlaps with Radish's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.0%) — Radish will thrive.

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

10
successive plantings in your 175-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
1.0″/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 1.6" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 2.8" 0" ❄️ Dormant
Apr 2.2" 3.8" 0" ✅ Rainfall sufficient
May 2.2" 4.4" 0" ✅ Rainfall sufficient
Jun 2.2" 5.5" 0" ✅ Rainfall sufficient
Jul 2.2" 4.1" 0" ✅ Rainfall sufficient
Aug 2.2" 3.9" 0" ✅ Rainfall sufficient
Sep 2.2" 3.3" 0" ✅ Rainfall sufficient
Oct 2.2" 3.4" 0" ✅ Rainfall sufficient
Nov 2.6" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Oakland 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 ~520 GDD — county provides 3,193 GDD Excellent fit

Radish Planting Timeline — Oakland County, MI

Radish Planting Calendar

Activity When Date Range
Direct Sow April 14 Apr 14 – May 5
Harvest May 12 May 12 – Jun 2
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: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

175 days in Oakland County

Growing Tips for Radish in Oakland County

Direct sow Radish outdoors after April 28 in Oakland County when soil has warmed and frost danger has passed.

Summer highs in Oakland County reach 91°F — grow Radish as a spring or fall crop. Use shade cloth if planting in summer.

Your generous 175.0-day season in Oakland 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 Oakland County, MI?

Oakland County is in Zone 6a with an average last frost of April 28. Plan your Radish planting based on this frost date — see the calendar above for exact timing.

What planting zone is Oakland County, MI?

Oakland County, Michigan is in USDA Hardiness Zone 6a. The average last spring frost is April 28 and first fall frost is October 20.

🌱

Your Oakland County Garden Planner — Free

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

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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 Oakland County, MI. 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.