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When to Plant Radicchio in Blaine County, OK

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.

Blaine County, Oklahoma is in USDA Zone 7a. The average last spring frost is April 10 and the first fall frost is October 27, giving you a growing season of approximately 200 days.

At an elevation of 719 feet, Blaine County receives approximately 30.2 inches of rainfall annually with predominantly loam soil. Summer highs average 90ยฐF, providing good warmth for Radicchio during the growing season.

Blaine County, OK (Zone 7a) Long season
200 days
Last Spring Frost April 10
200 growing days
First Fall Frost October 27

Blaine County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (102 days to spare)
Start indoors: Mar 2 Transplant: Apr 6 🍅 Harvest: Jun 8 – Jul 13
Recommended (50%) ✓ Fits season (102 days to spare)
Start indoors: Mar 6 Transplant: Apr 10 🍅 Harvest: Jun 12 – Jul 17
Safe Start (90%) ✓ Fits season (104 days to spare)
Start indoors: Mar 19 Transplant: Apr 23 🍅 Harvest: Jun 25 – Jul 30

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 Blaine County

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

Soil pH

Your soil pH (6.3โ€“7.4) overlaps with Radicchio's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

The loam soil in Blaine County is excellent for Radicchio โ€” 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

3
successive plantings in your 200-day season

Sow every 6.9 weeks. Last sowing by Aug 08 to harvest before frost.

For a dedicated fall crop, sow by Aug 18.

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 117 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 โ€” 0.7" 0" โ„๏ธ Dormant
Feb โ€” 0.9" 0" โ„๏ธ Dormant
Mar โ€” 1.8" 0" โ„๏ธ Dormant
Apr 3" 3.4" 0" โœ… Rainfall sufficient
May 3" 4.4" 0" โœ… Rainfall sufficient
Jun 3" 4.4" 0" โœ… Rainfall sufficient
Jul 3" 3.7" 0" โœ… Rainfall sufficient
Aug 3" 3.7" 0" โœ… Rainfall sufficient
Sep 3" 3.2" 0" โœ… Rainfall sufficient
Oct 3" 2" 1" ๐Ÿ’ง Light watering
Nov โ€” 1.1" 0" โ„๏ธ Dormant
Dec โ€” 0.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Blaine County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 3,500 GDD Excellent fit

Radicchio Planting Timeline โ€” Blaine County, OK

Radicchio Planting Calendar

Activity When Date Range
Start Indoors March 6 Mar 6 โ€“ Mar 20
Transplant Outdoors April 10 Apr 10 โ€“ Apr 24
Direct Sow March 27 Mar 27 โ€“ Apr 17
Harvest June 12 Jun 12 โ€“ Jul 17
Fall Sowing August 18 Aug 18 โ€“ Sep 1

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.7"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

60โ€“80 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 7a

๐Ÿ“† Growing Season

200 days in Blaine County

Growing Tips for Radicchio in Blaine County

Direct sow Radicchio outdoors after April 10 in Blaine 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 Blaine County, OK?

Blaine County is in Zone 7a with an average last frost of April 10. Plan your Radicchio planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Blaine County, OK?

Blaine County, Oklahoma is in USDA Hardiness Zone 7a. The average last spring frost is April 10 and first fall frost is October 27.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Blaine County gardeners in Zone 7a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Blaine County, OK. Local conditions may vary. Last updated: April 2026.