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When to Plant Radicchio in Plaquemines Parish, LA

Plaquemines Parish, Louisiana Zone 9b May

This month in Plaquemines Parish, Louisiana

Your garden in Plaquemines Parish, Louisiana is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost February 6
Avg. first frost December 7
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Harvest radicchio as they ripen

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

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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.

Plaquemines Parish, Louisiana is in USDA Zone 9b. The average last spring frost is February 6 and the first fall frost is December 7, giving you a growing season of approximately 304 days.

At an elevation of 386 feet, Plaquemines Parish receives approximately 50.2 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 99°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.

Plaquemines Parish, LA (Zone 9b) Year-round
304 days
Last Spring Frost February 6
304 growing days
First Fall Frost December 7

Plaquemines Parish Soil Profile

Soil Type

Sandy Loam

Soil pH

4.8-6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (212 days to spare)
Start indoors: Dec 28 Transplant: Jan 25 🍅 Harvest: Mar 29 – May 3
Recommended (50%) ✓ Fits season (206 days to spare)
Start indoors: Jan 9 Transplant: Feb 6 🍅 Harvest: Apr 10 – May 15
Safe Start (90%) ✓ Fits season (191 days to spare)
Start indoors: Feb 9 Transplant: Mar 9 🍅 Harvest: May 11 – Jun 15

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 Plaquemines Parish

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

Soil pH

Your soil pH (4.8–6.0) is more acidic than Radicchio prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

Sandy soil in Plaquemines Parish 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 moderate (2.0%). Annual compost additions will help Radicchio.

How to Plant Radicchio

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Radicchio

6
successive plantings in your 304-day season

Sow every 6.9 weeks. Last sowing by Sep 18 to harvest before frost.

For a dedicated fall crop, sow by Oct 12.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.7″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 28 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 3.7" 0" ❄️ Dormant
Feb 3" 3.5" 0" ✅ Rainfall sufficient
Mar 3" 4.4" 0" ✅ Rainfall sufficient
Apr 3" 3.3" 0" ✅ Rainfall sufficient
May 3" 4.2" 0" ✅ Rainfall sufficient
Jun 3" 5" 0" ✅ Rainfall sufficient
Jul 3" 5.9" 0" ✅ Rainfall sufficient
Aug 3" 5.2" 0" ✅ Rainfall sufficient
Sep 3" 3.4" 0" ✅ Rainfall sufficient
Oct 3" 3.3" 0" ✅ Rainfall sufficient
Nov 3" 3.7" 0" ✅ Rainfall sufficient
Dec 3" 4.5" 0" ✅ Rainfall sufficient

Water needs are for active growing months only (Feb–Dec in Plaquemines Parish). 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 ~1,698 GDD — county provides 7,396 GDD Excellent fit

Radicchio Planting Timeline — Plaquemines Parish, LA

Radicchio Planting Calendar

Activity When Date Range
Start Indoors January 9 Jan 9 – Jan 23
Transplant Outdoors February 6 Feb 6 – Feb 20
Direct Sow January 16 Jan 16 – Feb 6
Harvest April 10 Apr 10 – May 15
Fall Sowing October 12 Oct 12 – Oct 26

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 9b

📆 Growing Season

304 days in Plaquemines Parish

Growing Tips for Radicchio in Plaquemines Parish

Direct sow Radicchio outdoors after February 06 in Plaquemines Parish when soil has warmed and frost danger has passed.

Sandy soil in Plaquemines Parish 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 99°F in Plaquemines Parish, 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 Plaquemines Parish, LA?

Plaquemines Parish is in Zone 9b with an average last frost of February 6. Plan your Radicchio planting based on this frost date — see the calendar above for exact timing.

What planting zone is Plaquemines Parish, LA?

Plaquemines Parish, Louisiana is in USDA Hardiness Zone 9b. The average last spring frost is February 6 and first fall frost is December 7.

🌱

Your Plaquemines Parish Garden Planner — Free

A 24-page printable planner built for Plaquemines Parish (Zone 9b). 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 Plaquemines Parish, LA. 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.