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When to Plant Radicchio in Sebastian County, AR

Sebastian County, Arkansas Zone 8a May

Top priorities for Sebastian County, Arkansas gardeners in May

A quick May briefing for Sebastian County, Arkansas gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 5
Avg. first frost October 31
Soil temp (4") 68°F
Watering Moderate
Pest pressure Moderate
Daylight 13.8 hrs
  1. Start radicchio under lights

    Label every cell. You will absolutely forget which is which otherwise.

June will be here before you know it — start on
  • 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.

Sebastian County, Arkansas is in USDA Zone 8a. The average last spring frost is April 5 and the first fall frost is October 31, giving you a growing season of approximately 209 days.

At an elevation of 796 feet, Sebastian County receives approximately 45 inches of rainfall annually with predominantly silt loam soil. Summer highs average 93°F, providing good warmth for Radicchio during the growing season.

Sebastian County, AR (Zone 8a) Long season
209 days
Last Spring Frost April 5
209 growing days
First Fall Frost October 31

Sebastian County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (118 days to spare)
Start indoors: Feb 18 Transplant: Mar 25 🍅 Harvest: May 27 – Jul 1
Recommended (50%) ✓ Fits season (111 days to spare)
Start indoors: Mar 1 Transplant: Apr 5 🍅 Harvest: Jun 7 – Jul 12
Safe Start (90%) ✓ Fits season (121 days to spare)
Start indoors: Mar 12 Transplant: Apr 16 🍅 Harvest: Jun 18 – Jul 23

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 Sebastian County

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

Soil pH

Your soil pH (5.3–6.8) overlaps with Radicchio's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.0%). 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 209-day season

Sow every 6.9 weeks. Last sowing by Aug 12 to harvest before frost.

For a dedicated fall crop, sow by Aug 22.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 3.5" 0" ❄️ Dormant
Feb 4" 0" ❄️ Dormant
Mar 4.6" 0" ❄️ Dormant
Apr 3" 3" 0" ✅ Rainfall sufficient
May 3" 3.5" 0" ✅ Rainfall sufficient
Jun 3" 3.5" 0" ✅ Rainfall sufficient
Jul 3" 4.8" 0" ✅ Rainfall sufficient
Aug 3" 4.4" 0" ✅ Rainfall sufficient
Sep 3" 3" 0" ✅ Rainfall sufficient
Oct 3" 3.2" 0" ✅ Rainfall sufficient
Nov 3.8" 0" ❄️ Dormant
Dec 3.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Sebastian 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 ~1,382 GDD — county provides 4,127 GDD Excellent fit

Radicchio Planting Timeline — Sebastian County, AR

Radicchio Planting Calendar

Activity When Date Range
Start Indoors March 1 Mar 1 – Mar 15
Transplant Outdoors April 5 Apr 5 – Apr 19
Direct Sow March 22 Mar 22 – Apr 12
Harvest June 7 Jun 7 – Jul 12
Fall Sowing August 22 Aug 22 – Sep 5

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 Fall Sowing
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.7"/week · Natural rainfall sufficient

📅 Days to Maturity

60–80 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 8a

📆 Growing Season

209 days in Sebastian County

Growing Tips for Radicchio in Sebastian County

Direct sow Radicchio outdoors after April 05 in Sebastian 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 Sebastian County, AR?

Sebastian County is in Zone 8a with an average last frost of April 5. Plan your Radicchio planting based on this frost date — see the calendar above for exact timing.

What planting zone is Sebastian County, AR?

Sebastian County, Arkansas is in USDA Hardiness Zone 8a. The average last spring frost is April 5 and first fall frost is October 31.

🌱

Your Sebastian County Garden Planner — Free

A 24-page printable planner built for Sebastian 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 Sebastian County, AR. 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.