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When to Plant Radicchio in Cotton County, OK

Cotton County, Oklahoma Zone 8a May

Your May game plan for Cotton County, Oklahoma

Your Cotton County, Oklahoma garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost March 25
Avg. first frost November 10
Soil temp (4") 66°F
Watering High
Pest pressure Moderate
Daylight 13.8 hrs
  1. Pick radicchio

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

Looking ahead to June
  • First harvests: radicchio

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Radicchio is an Italian chicory with stunning red and white leaves and a pleasantly bitter flavor. It forms tight heads and is used in salads, grilled, or braised.

Cotton County, Oklahoma is in USDA Zone 8a. The average last spring frost is March 25 and the first fall frost is November 10, giving you a growing season of approximately 230 days.

At an elevation of 1,015 feet, Cotton County receives approximately 20.6 inches of rainfall annually with predominantly loam soil. Summer highs average 92°F, providing good warmth for Radicchio during the growing season.

Cotton County, OK (Zone 8a) Long season
230 days
Last Spring Frost March 25
230 growing days
First Fall Frost November 10
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Cotton County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (133 days to spare)
Start indoors: Feb 7 Transplant: Mar 14 🍅 Harvest: May 16 – Jun 20
Recommended (50%) ✓ Fits season (132 days to spare)
Start indoors: Feb 18 Transplant: Mar 25 🍅 Harvest: May 27 – Jul 1
Safe Start (90%) ✓ Fits season (125 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: Jun 17 – Jul 22

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 Cotton County

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

Soil pH

Your soil pH (6.3–7.5) overlaps with Radicchio's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.8%). Annual compost additions will help Radicchio.

How to Plant Radicchio

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

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

Succession Planting Radicchio

4
successive plantings in your 230-day season

Sow every 6.9 weeks. Last sowing by Aug 22 to harvest before frost.

For a dedicated fall crop, sow by Sep 01.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.4″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 663 gal / 100 sq ft

Monthly Watering Guide for Radicchio

Radicchio needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Radicchio Needs Rainfall You Supplement Action
Jan 0.5" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 3" 1.4" 1.6" 🚿 Regular watering
Apr 3" 2.2" 0.8" 💧 Light watering
May 3" 2.7" 0.3" 💧 Light watering
Jun 3" 2.9" 0.1" 💧 Light watering
Jul 3" 2.9" 0.1" 💧 Light watering
Aug 3" 2.6" 0.4" 💧 Light watering
Sep 3" 1.9" 1.1" 💧 Light watering
Oct 3" 1.5" 1.5" 🚿 Regular watering
Nov 3" 0.8" 2.2" 🚿 Regular watering
Dec 0.5" 0" ❄️ Dormant

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

Radicchio 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.

Radicchio needs ~1,330 GDD — county provides 4,370 GDD Excellent fit

Radicchio Planting Timeline — Cotton County, OK

Radicchio Planting Calendar

Activity When Date Range
Start Indoors February 18 Feb 18 – Mar 4
Transplant Outdoors March 25 Mar 25 – Apr 8
Direct Sow March 11 Mar 11 – Apr 1
Harvest May 27 May 27 – Jul 1
Fall Sowing September 1 Sep 1 – Sep 15

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors Transplant Outdoors Direct Sow
April Transplant Outdoors Direct Sow
May Harvest
June Harvest
July Harvest
August
September Fall Sowing
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.7"/week · 1-2 times/week

📅 Days to Maturity

60–80 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 8a

📆 Growing Season

230 days in Cotton County

Growing Tips for Radicchio in Cotton County

Direct sow Radicchio outdoors after March 25 in Cotton County when soil has warmed and frost danger has passed.

Common pests for Radicchio in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Start in late summer for fall harvest. The red color develops with cool nights and light frost. Harvest when heads are firm and compact.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Radicchio in Cotton County, OK?

Cotton County is in Zone 8a with an average last frost of March 25. Plan your Radicchio planting based on this frost date — see the calendar above for exact timing.

What planting zone is Cotton County, OK?

Cotton County, Oklahoma is in USDA Hardiness Zone 8a. The average last spring frost is March 25 and first fall frost is November 10.

🌱

Your Cotton County Garden Planner — Free

A 24-page printable planner built for Cotton County (Zone 8a). 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 Cotton 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.