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When to Plant Radicchio in St. Lucie County, FL

St. Lucie County, Florida Zone 10a May

St. Lucie County, Florida gardeners: here's your May plan

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost January 29
Avg. first frost December 16
Soil temp (4") 78°F
Watering Moderate
Pest pressure High
Daylight 13.4 hrs
  1. Basket week: radicchio

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

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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.

St. Lucie County, Florida is in USDA Zone 10a. The average last spring frost is January 29 and the first fall frost is December 16, giving you a growing season of approximately 321 days.

At an elevation of 185 feet, St. Lucie County receives approximately 56.2 inches of rainfall annually with predominantly sand soil. Summer highs average 89°F, providing good warmth for Radicchio during the growing season. 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.

St. Lucie County, FL (Zone 10a) Year-round
321 days
Last Spring Frost January 29
321 growing days
First Fall Frost December 16

St. Lucie County Soil Profile

Soil Type

Sand

Soil pH

4.8-5.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (226 days to spare)
Start indoors: Dec 22 Transplant: Jan 19 🍅 Harvest: Mar 23 – Apr 27
Recommended (50%) ✓ Fits season (223 days to spare)
Start indoors: Jan 1 Transplant: Jan 29 🍅 Harvest: Apr 2 – May 7
Safe Start (90%) ✓ Fits season (210 days to spare)
Start indoors: Jan 21 Transplant: Feb 18 🍅 Harvest: Apr 22 – May 27

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 St. Lucie County

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

Soil pH

Your soil pH (4.8–5.8) is more acidic than Radicchio prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Radicchio.

Organic Matter

Organic matter is low (1.3%). 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 8 weeks before your first frost date for a fall harvest.

Succession Planting Radicchio

6
successive plantings in your 321-day season

Sow every 6.9 weeks. Last sowing by Sep 27 to harvest before frost.

For a dedicated fall crop, sow by Oct 21.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.7″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 609 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" 2.3" 0.7" 💧 Light watering
Feb 3" 2.7" 0.3" 💧 Light watering
Mar 3" 3.3" 0" ✅ Rainfall sufficient
Apr 3" 2.2" 0.8" 💧 Light watering
May 3" 3.1" 0" ✅ Rainfall sufficient
Jun 3" 8.1" 0" ✅ Rainfall sufficient
Jul 3" 9" 0" ✅ Rainfall sufficient
Aug 3" 8.6" 0" ✅ Rainfall sufficient
Sep 3" 7.5" 0" ✅ Rainfall sufficient
Oct 3" 5" 0" ✅ Rainfall sufficient
Nov 3" 2.1" 0.9" 💧 Light watering
Dec 3" 2.2" 0.8" 💧 Light watering

Water needs are for active growing months only (Jan–Dec in St. Lucie 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 ~1,172 GDD — county provides 5,393 GDD Excellent fit

Radicchio Planting Timeline — St. Lucie County, FL

Radicchio Planting Calendar

Activity When Date Range
Start Indoors January 1 Jan 1 – Jan 15
Transplant Outdoors January 29 Jan 29 – Feb 12
Direct Sow January 8 Jan 8 – Jan 29
Harvest April 2 Apr 2 – May 7
Fall Sowing October 21 Oct 21 – Nov 4

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

Month-by-Month Timeline

MonthActivities
January Start Indoors Transplant Outdoors Direct Sow
February Transplant Outdoors
March
April Harvest
May Harvest
June
July
August
September
October Fall Sowing
November Fall Sowing
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 10a

📆 Growing Season

321 days in St. Lucie County

Growing Tips for Radicchio in St. Lucie County

Direct sow Radicchio outdoors after January 29 in St. Lucie County when soil has warmed and frost danger has passed.

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

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 St. Lucie County, FL?

St. Lucie County is in Zone 10a with an average last frost of January 29. Plan your Radicchio planting based on this frost date — see the calendar above for exact timing.

What planting zone is St. Lucie County, FL?

St. Lucie County, Florida is in USDA Hardiness Zone 10a. The average last spring frost is January 29 and first fall frost is December 16.

🌱

Your St. Lucie County Garden Planner — Free

A 24-page printable planner built for St. Lucie County (Zone 10a). 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 St. Lucie County, FL. 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.