When to Plant Radicchio in Williamsburg County, SC
May in the garden — Williamsburg County, South Carolina
Welcome to May in Zone 8b. These are the moves that will have the biggest impact on your growing season.
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Bring in the radicchio
Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.
Before June arrives, get these ready
- First harvests: radicchio
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.
Williamsburg County, South Carolina is in USDA Zone 8b. The average last spring frost is March 22 and the first fall frost is November 13, giving you a growing season of approximately 236 days.
At an elevation of 139 feet, Williamsburg County receives approximately 52.7 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 92°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.
Williamsburg County Soil Profile
Soil Type
Sandy Loam
Soil pH
5-6.4
Drainage
Well Drained
Plant Planting Risk Windows
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 Williamsburg County
How your county's soil matches Radicchio's growing requirements.
Soil pH
Your soil pH (5.0–6.4) is more acidic than Radicchio prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
Sandy soil in Williamsburg 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 (1.9%). Add 2-3 inches of compost before planting Radicchio.
How to Plant Radicchio
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Radicchio
Sow every 6.9 weeks. Last sowing by Aug 25 to harvest before frost.
For a dedicated fall crop, sow by Sep 04.
Plant Water Budget
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 | — | 4.2" | 0" | ❄️ Dormant |
| Feb | — | 4.5" | 0" | ❄️ Dormant |
| Mar | 3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Apr | 3" | 4.5" | 0" | ✅ Rainfall sufficient |
| May | 3" | 4.1" | 0" | ✅ Rainfall sufficient |
| Jun | 3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Jul | 3" | 5.9" | 0" | ✅ Rainfall sufficient |
| Aug | 3" | 5.2" | 0" | ✅ Rainfall sufficient |
| Sep | 3" | 3.6" | 0" | ✅ Rainfall sufficient |
| Oct | 3" | 3" | 0" | ✅ Rainfall sufficient |
| Nov | 3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Dec | — | 4.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Williamsburg 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 Planting Timeline — Williamsburg County, SC
Radicchio Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 15 | Feb 15 – Mar 1 |
| Transplant Outdoors | March 22 | Mar 22 – Apr 5 |
| Direct Sow | March 8 | Mar 8 – Mar 29 |
| Harvest | May 24 | May 24 – Jun 28 |
| Fall Sowing | September 4 | Sep 4 – Sep 18 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors Transplant Outdoors Direct Sow |
| April | Transplant Outdoors |
| May | Harvest |
| June | Harvest |
| July | — |
| August | — |
| 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: too_acidic
🗺️ USDA Zone
Zone 8b
📆 Growing Season
236 days in Williamsburg County
Growing Tips for Radicchio in Williamsburg County
Direct sow Radicchio outdoors after March 22 in Williamsburg County when soil has warmed and frost danger has passed.
Sandy soil in Williamsburg 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
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Check more plant combinations with our Companion Planting Checker →
Radicchio in Other Locations
Frequently Asked Questions
When should I plant Radicchio in Williamsburg County, SC?
Williamsburg County is in Zone 8b with an average last frost of March 22. Plan your Radicchio planting based on this frost date — see the calendar above for exact timing.
What planting zone is Williamsburg County, SC?
Williamsburg County, South Carolina is in USDA Hardiness Zone 8b. The average last spring frost is March 22 and first fall frost is November 13.
Your Williamsburg County Garden Planner — Free
A 24-page printable planner built for Williamsburg County (Zone 8b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.