When to Plant Radicchio in Durham County, NC
Your May game plan for Durham County, North Carolina
May is a pivotal month for Durham County, North Carolina gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Start radicchio under lights
These need a head start before your last frost (April 2). Sow into cells now so you're ready to transplant in a few weeks.
A few tasks this May that'll pay off in June
- 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.
Durham County, North Carolina is in USDA Zone 8a. The average last spring frost is April 2 and the first fall frost is November 3, giving you a growing season of approximately 215 days.
At an elevation of 727 feet, Durham County receives approximately 40.1 inches of rainfall annually with predominantly clay loam soil. Summer highs average 90°F, providing good warmth for Radicchio during the growing season. Clay soil retains moisture well for Radicchio, but amend with compost to improve drainage and prevent root rot.
Durham County Soil Profile
Soil Type
Clay Loam
Soil pH
5.6-6.7
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 Durham County
How your county's soil matches Radicchio's growing requirements.
Soil pH
Your soil pH (5.6–6.7) overlaps with Radicchio's range (6.0–7.0), though not a perfect match.
Soil Texture
The clay loam soil in Durham County is excellent for Radicchio — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.4%). Annual compost additions will help 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 15 to harvest before frost.
For a dedicated fall crop, sow by Aug 25.
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 | — | 3.6" | 0" | ❄️ Dormant |
| Feb | — | 3.3" | 0" | ❄️ Dormant |
| Mar | — | 3.8" | 0" | ❄️ Dormant |
| Apr | 3" | 2.7" | 0.3" | 💧 Light watering |
| May | 3" | 3.1" | 0" | ✅ Rainfall sufficient |
| Jun | 3" | 3.3" | 0" | ✅ Rainfall sufficient |
| Jul | 3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Aug | 3" | 3.8" | 0" | ✅ Rainfall sufficient |
| Sep | 3" | 3" | 0" | ✅ Rainfall sufficient |
| Oct | 3" | 2.4" | 0.6" | 💧 Light watering |
| Nov | 3" | 3.4" | 0" | ✅ Rainfall sufficient |
| Dec | — | 3.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Nov in Durham 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 — Durham County, NC
Radicchio Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 26 | Feb 26 – Mar 12 |
| Transplant Outdoors | April 2 | Apr 2 – Apr 16 |
| Direct Sow | March 19 | Mar 19 – Apr 9 |
| Harvest | June 4 | Jun 4 – Jul 9 |
| Fall Sowing | August 25 | Aug 25 – Sep 8 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| 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
215 days in Durham County
Growing Tips for Radicchio in Durham County
Direct sow Radicchio outdoors after April 02 in Durham County when soil has warmed and frost danger has passed.
With Durham County's clay soil (31% clay), work in 3-4 inches of compost before planting Radicchio. Avoid tilling when soil is wet to prevent compaction.
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 Durham County, NC?
Durham County is in Zone 8a with an average last frost of April 2. Plan your Radicchio planting based on this frost date — see the calendar above for exact timing.
What planting zone is Durham County, NC?
Durham County, North Carolina is in USDA Hardiness Zone 8a. The average last spring frost is April 2 and first fall frost is November 3.
Your Durham County Garden Planner — Free
A 24-page printable planner built for Durham 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.