Blog

When to Plant Radish in Seminole County, OK

Seminole County, Oklahoma Zone 7b May

What to do in May

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

Avg. last frost March 31
Avg. first frost November 6
Soil temp (4") 69°F
Watering Moderate
Pest pressure Moderate
Daylight 13.8 hrs
  1. Basket week: radish

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

Instant PDF download. No spam, unsubscribe any time.

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.

Seminole County, Oklahoma is in USDA Zone 7b. The average last spring frost is March 31 and the first fall frost is November 6, giving you a growing season of approximately 220 days.

At an elevation of 961 feet, Seminole County receives approximately 20.7 inches of rainfall annually with predominantly loam soil. Summer highs average 94°F, providing good warmth for Radish during the growing season.

Seminole County, OK (Zone 7b) Long season
220 days
Last Spring Frost March 31
220 growing days
First Fall Frost November 6
Share this guide:

Seminole County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (169 days to spare)
Transplant: Mar 24 🍅 Harvest: Apr 21 – May 12
Recommended (50%) ✓ Fits season (171 days to spare)
Transplant: Mar 31 🍅 Harvest: Apr 28 – May 19
Safe Start (90%) ✓ Fits season (173 days to spare)
Transplant: Apr 15 🍅 Harvest: May 13 – Jun 3

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 Seminole County

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

Soil pH

Your soil pH (6.7–7.5) is more alkaline than Radish prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.9%). 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

12
successive plantings in your 220-day season

Sow every 2.4 weeks. Last sowing by Oct 02 to harvest before frost.

For a dedicated fall crop, sow by Aug 28.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.4″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 246 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 0.6" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 2.2" 1.4" 0.8" 💧 Light watering
Apr 2.2" 2.1" 0.1" 💧 Light watering
May 2.2" 3.2" 0" ✅ Rainfall sufficient
Jun 2.2" 3.3" 0" ✅ Rainfall sufficient
Jul 2.2" 2.4" 0" ✅ Rainfall sufficient
Aug 2.2" 2.8" 0" ✅ Rainfall sufficient
Sep 2.2" 1.7" 0.5" 💧 Light watering
Oct 2.2" 1.3" 0.9" 💧 Light watering
Nov 2.2" 0.8" 1.4" 🚿 Regular watering
Dec 0.5" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Seminole 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 ~584 GDD — county provides 4,510 GDD Excellent fit

Radish Planting Timeline — Seminole County, OK

Radish Planting Calendar

Activity When Date Range
Direct Sow March 17 Mar 17 – Apr 7
Harvest April 14 Apr 14 – May 5
Fall Sowing August 28 Aug 28 – Sep 11

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Only during dry spells

📅 Days to Maturity

22–35 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 7b

📆 Growing Season

220 days in Seminole County

Growing Tips for Radish in Seminole County

Direct sow Radish outdoors after March 31 in Seminole County when soil has warmed and frost danger has passed.

Summer highs in Seminole County reach 94°F — grow Radish as a spring or fall crop. Use shade cloth if planting in summer.

Your generous 220.0-day season in Seminole 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 Seminole County, OK?

Seminole County is in Zone 7b with an average last frost of March 31. Plan your Radish planting based on this frost date — see the calendar above for exact timing.

What planting zone is Seminole County, OK?

Seminole County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is March 31 and first fall frost is November 6.

🌱

Your Seminole County Garden Planner — Free

A 24-page printable planner built for Seminole County (Zone 7b). 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 Seminole County, OK. 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.