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When to Plant Radicchio in Payne County, OK

Payne County, Oklahoma Zone 7a April

Your April planting checklist for Payne County, Oklahoma

Welcome to April in Zone 7a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 9
Avg. first frost October 25
Soil temp (4") 57°F
Watering High
Pest pressure Moderate
Daylight 12.9 hrs
  1. Transplant radicchio outside

    Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.

May prep starts now
  • Starting indoors: 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.

Payne County, Oklahoma is in USDA Zone 7a. The average last spring frost is April 9 and the first fall frost is October 25, giving you a growing season of approximately 199 days.

At an elevation of 523 feet, Payne County receives approximately 21.7 inches of rainfall annually with predominantly loam soil. Summer highs average 88°F, providing good warmth for Radicchio during the growing season.

Payne County, OK (Zone 7a) Moderate season
199 days
Last Spring Frost April 9
199 growing days
First Fall Frost October 25
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Payne County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (99 days to spare)
Start indoors: Feb 28 Transplant: Apr 4 🍅 Harvest: Jun 6 – Jul 11
Recommended (50%) ✓ Fits season (101 days to spare)
Start indoors: Mar 5 Transplant: Apr 9 🍅 Harvest: Jun 11 – Jul 16
Safe Start (90%) ✓ Fits season (101 days to spare)
Start indoors: Mar 21 Transplant: Apr 25 🍅 Harvest: Jun 27 – Aug 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 Payne County

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

Soil pH

Your soil pH (6.5–7.7) is more alkaline than Radicchio prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.3%) — Radicchio will thrive.

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 199-day season

Sow every 6.9 weeks. Last sowing by Aug 06 to harvest before frost.

For a dedicated fall crop, sow by Aug 16.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.5″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 514 gal / 100 sq ft
Drought risk

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

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 0.6" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.2" 0" ❄️ Dormant
Apr 3" 2.2" 0.8" 💧 Light watering
May 3" 3.2" 0" ✅ Rainfall sufficient
Jun 3" 3.7" 0" ✅ Rainfall sufficient
Jul 3" 2.9" 0.1" 💧 Light watering
Aug 3" 2.5" 0.5" 💧 Light watering
Sep 3" 1.9" 1.1" 💧 Light watering
Oct 3" 1.4" 1.6" 🚿 Regular watering
Nov 0.8" 0" ❄️ Dormant
Dec 0.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Payne 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 ~1,120 GDD — county provides 3,184 GDD Excellent fit

Radicchio Planting Timeline — Payne County, OK

Radicchio Planting Calendar

Activity When Date Range
Start Indoors March 5 Mar 5 – Mar 19
Transplant Outdoors April 9 Apr 9 – Apr 23
Direct Sow March 26 Mar 26 – Apr 16
Harvest June 11 Jun 11 – Jul 16
Fall Sowing August 16 Aug 16 – Aug 30

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
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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: too_alkaline

🗺️ USDA Zone

Zone 7a

📆 Growing Season

199 days in Payne County

Growing Tips for Radicchio in Payne County

Direct sow Radicchio outdoors after April 09 in Payne 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 Payne County, OK?

Payne County is in Zone 7a with an average last frost of April 9. Plan your Radicchio planting based on this frost date — see the calendar above for exact timing.

What planting zone is Payne County, OK?

Payne County, Oklahoma is in USDA Hardiness Zone 7a. The average last spring frost is April 9 and first fall frost is October 25.

🌱

Your Payne County Garden Planner — Free

A 24-page printable planner built for Payne County (Zone 7a). 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 Payne County, OK. Local conditions may vary. Last updated: April 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.