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When to Plant Radicchio in Martin County, TX

Martin County, Texas Zone 8a May

May in Martin County, Texas — your action list

Each item below is timed to Martin County, Texas's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost March 25
Avg. first frost November 12
Soil temp (4") 53°F
Watering Critical
Pest pressure Moderate
Daylight 13.7 hrs
  1. Start harvesting radicchio

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Looking ahead to June
  • 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.

Martin County, Texas is in USDA Zone 8a. The average last spring frost is March 25 and the first fall frost is November 12, giving you a growing season of approximately 232 days.

At an elevation of 4,922 feet, Martin County receives approximately 50.2 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 100°F, so Radicchio may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Radicchio will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Radicchio root diseases.

Martin County, TX (Zone 8a) Long season
232 days
Last Spring Frost March 25
232 growing days
First Fall Frost November 12
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Martin County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.2-8.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (132 days to spare)
Start indoors: Feb 10 Transplant: Mar 17 🍅 Harvest: May 19 – Jun 23
Recommended (50%) ✓ Fits season (134 days to spare)
Start indoors: Feb 18 Transplant: Mar 25 🍅 Harvest: May 27 – Jul 1
Safe Start (90%) ✓ Fits season (128 days to spare)
Start indoors: Mar 9 Transplant: Apr 13 🍅 Harvest: Jun 15 – Jul 20

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 Martin County

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

Soil pH

Your soil pH (7.2–8.7) is more alkaline than Radicchio prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Martin County warms quickly in spring but drains fast. Radicchio will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is low (1.0%). Add 2-3 inches of compost before planting 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 232-day season

Sow every 6.9 weeks. Last sowing by Aug 24 to harvest before frost.

For a dedicated fall crop, sow by Sep 03.

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
Drought risk

Water stress score is 8/10 — 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 2.9" 0" ❄️ Dormant
Feb 3" 0" ❄️ Dormant
Mar 3" 2.4" 0.6" 💧 Light watering
Apr 3" 1.9" 1.1" 💧 Light watering
May 3" 0.9" 2.1" 🚿 Regular watering
Jun 3" 1.4" 1.6" 🚿 Regular watering
Jul 3" 9.2" 0" ✅ Rainfall sufficient
Aug 3" 10.1" 0" ✅ Rainfall sufficient
Sep 3" 7" 0" ✅ Rainfall sufficient
Oct 3" 4.9" 0" ✅ Rainfall sufficient
Nov 3" 2.8" 0.2" 💧 Light watering
Dec 3.7" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Martin 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 ~1,750 GDD — county provides 5,800 GDD Excellent fit

Radicchio Planting Timeline — Martin County, TX

Radicchio Planting Calendar

Activity When Date Range
Start Indoors February 18 Feb 18 – Mar 4
Transplant Outdoors March 25 Mar 25 – Apr 8
Direct Sow March 11 Mar 11 – Apr 1
Harvest May 27 May 27 – Jul 1
Fall Sowing September 3 Sep 3 – Sep 17

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 8a

📆 Growing Season

232 days in Martin County

Growing Tips for Radicchio in Martin County

Direct sow Radicchio outdoors after March 25 in Martin County when soil has warmed and frost danger has passed.

Sandy soil in Martin County dries quickly — mulch Radicchio with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 100°F in Martin County, provide afternoon shade for Radicchio and water deeply in the morning.

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 Martin County, TX?

Martin County is in Zone 8a with an average last frost of March 25. Plan your Radicchio planting based on this frost date — see the calendar above for exact timing.

What planting zone is Martin County, TX?

Martin County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 25 and first fall frost is November 12.

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Your Martin County Garden Planner — Free

A 24-page printable planner built for Martin 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 Martin County, TX. 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.