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When to Plant Radicchio in Tulsa County, OK

Tulsa County, Oklahoma Zone 7b May

Tulsa County, Oklahoma gardeners: here's your May plan

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

Avg. last frost April 7
Avg. first frost October 26
Soil temp (4") 69°F
Watering Low
Pest pressure Moderate
Daylight 13.9 hrs
  1. Fire up the seed-starting tray: radicchio

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

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.

Tulsa County, Oklahoma is in USDA Zone 7b. The average last spring frost is April 7 and the first fall frost is October 26, giving you a growing season of approximately 202 days.

At an elevation of 752 feet, Tulsa County receives approximately 28.7 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Radicchio during the growing season.

Tulsa County, OK (Zone 7b) Long season
202 days
Last Spring Frost April 7
202 growing days
First Fall Frost October 26

Tulsa County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (102 days to spare)
Start indoors: Feb 26 Transplant: Apr 2 🍅 Harvest: Jun 4 – Jul 9
Recommended (50%) ✓ Fits season (104 days to spare)
Start indoors: Mar 3 Transplant: Apr 7 🍅 Harvest: Jun 9 – Jul 14
Safe Start (90%) ✓ Fits season (104 days to spare)
Start indoors: Mar 20 Transplant: Apr 24 🍅 Harvest: Jun 26 – Jul 31

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 Tulsa County

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

Soil pH

Your soil pH (6.8–7.1) overlaps with Radicchio's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.6%). 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

3
successive plantings in your 202-day season

Sow every 6.9 weeks. Last sowing by Aug 07 to harvest before frost.

For a dedicated fall crop, sow by Aug 17.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.6″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 186 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 1.7" 0" ❄️ Dormant
Apr 3" 3.5" 0" ✅ Rainfall sufficient
May 3" 4.5" 0" ✅ Rainfall sufficient
Jun 3" 4.9" 0" ✅ Rainfall sufficient
Jul 3" 3.4" 0" ✅ Rainfall sufficient
Aug 3" 3" 0" ✅ Rainfall sufficient
Sep 3" 2.4" 0.6" 💧 Light watering
Oct 3" 1.9" 1.1" 💧 Light watering
Nov 0.9" 0" ❄️ Dormant
Dec 0.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Tulsa 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 3,535 GDD Excellent fit

Radicchio Planting Timeline — Tulsa County, OK

Radicchio Planting Calendar

Activity When Date Range
Start Indoors March 3 Mar 3 – Mar 17
Transplant Outdoors April 7 Apr 7 – Apr 21
Direct Sow March 24 Mar 24 – Apr 14
Harvest June 9 Jun 9 – Jul 14
Fall Sowing August 17 Aug 17 – Aug 31

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

Month-by-Month Timeline

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

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

202 days in Tulsa County

Growing Tips for Radicchio in Tulsa County

Direct sow Radicchio outdoors after April 07 in Tulsa 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 Tulsa County, OK?

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

What planting zone is Tulsa County, OK?

Tulsa County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is April 7 and first fall frost is October 26.

🌱

Your Tulsa County Garden Planner — Free

A 24-page printable planner built for Tulsa 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 Tulsa 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.