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When to Plant Radicchio in Pittsburg County, OK

Pittsburg County, Oklahoma Zone 7b May

Your May gardening checklist

Here's what deserves your attention in Pittsburg County, Oklahoma this month. Everything below is tailored to Zone 7b and timed around your local frost dates.

Avg. last frost April 4
Avg. first frost November 1
Soil temp (4") 69°F
Watering Low
Pest pressure Moderate
Daylight 13.8 hrs
  1. Start radicchio indoors

    You're about 25 weeks out from your last frost — the perfect window to get these germinating indoors.

Coming up in June — start thinking about
  • 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.

Pittsburg County, Oklahoma is in USDA Zone 7b. The average last spring frost is April 4 and the first fall frost is November 1, giving you a growing season of approximately 211 days.

At an elevation of 620 feet, Pittsburg County receives approximately 32.6 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Radicchio during the growing season.

Pittsburg County, OK (Zone 7b) Long season
211 days
Last Spring Frost April 4
211 growing days
First Fall Frost November 1
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Pittsburg County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (117 days to spare)
Start indoors: Feb 19 Transplant: Mar 26 🍅 Harvest: May 28 – Jul 2
Recommended (50%) ✓ Fits season (113 days to spare)
Start indoors: Feb 28 Transplant: Apr 4 🍅 Harvest: Jun 6 – Jul 11
Safe Start (90%) ✓ Fits season (121 days to spare)
Start indoors: Mar 13 Transplant: Apr 17 🍅 Harvest: Jun 19 – Jul 24

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 Pittsburg County

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

Soil pH

Your soil pH (6.6–7.2) overlaps with Radicchio's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.7%). 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 211-day season

Sow every 6.9 weeks. Last sowing by Aug 13 to harvest before frost.

For a dedicated fall crop, sow by Aug 23.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.7″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 96 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 0.9" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.8" 0" ❄️ Dormant
Apr 3" 3.5" 0" ✅ Rainfall sufficient
May 3" 5.1" 0" ✅ Rainfall sufficient
Jun 3" 5.1" 0" ✅ Rainfall sufficient
Jul 3" 4.2" 0" ✅ Rainfall sufficient
Aug 3" 3.6" 0" ✅ Rainfall sufficient
Sep 3" 3.4" 0" ✅ Rainfall sufficient
Oct 3" 2" 1" 💧 Light watering
Nov 3" 1" 2" 🚿 Regular watering
Dec 1" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Pittsburg 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 ~1,225 GDD — county provides 3,692 GDD Excellent fit

Radicchio Planting Timeline — Pittsburg County, OK

Radicchio Planting Calendar

Activity When Date Range
Start Indoors February 28 Feb 28 – Mar 14
Transplant Outdoors April 4 Apr 4 – Apr 18
Direct Sow March 21 Mar 21 – Apr 11
Harvest June 6 Jun 6 – Jul 11
Fall Sowing August 23 Aug 23 – Sep 6

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.7"/week · Only during dry spells

📅 Days to Maturity

60–80 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

211 days in Pittsburg County

Growing Tips for Radicchio in Pittsburg County

Direct sow Radicchio outdoors after April 04 in Pittsburg 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 Pittsburg County, OK?

Pittsburg County is in Zone 7b with an average last frost of April 4. Plan your Radicchio planting based on this frost date — see the calendar above for exact timing.

What planting zone is Pittsburg County, OK?

Pittsburg County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is April 4 and first fall frost is November 1.

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Your Pittsburg County Garden Planner — Free

A 24-page printable planner built for Pittsburg 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.

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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 Pittsburg 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.