When to Plant Radicchio in Franklin County, ME
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.
Franklin County, Maine is in USDA Zone 4a. The average last spring frost is May 14 and the first fall frost is September 28, giving you a growing season of approximately 137 days.
At an elevation of 244 feet, Franklin County receives approximately 40.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Radicchio to ensure they mature before fall.
Franklin County Soil Profile
Soil Type
Silt Loam
Soil pH
5.2-6.6
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 Franklin County
How your county's soil matches Radicchio's growing requirements.
Soil pH
Your soil pH (5.2–6.6) is more acidic than Radicchio prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Franklin County is excellent for Radicchio — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.2%). Annual compost additions will help Radicchio.
How to Plant Radicchio
Fall planting: Sow 12 weeks before your first frost date for a fall harvest.
Succession Planting Radicchio
Sow every 6.9 weeks. Last sowing by Jul 10 to harvest before frost.
For a dedicated fall crop, sow by Jul 06.
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 | — | 3.2" | 0" | ❄️ Dormant |
| Feb | — | 2.6" | 0" | ❄️ Dormant |
| Mar | — | 3.9" | 0" | ❄️ Dormant |
| Apr | — | 3.1" | 0" | ❄️ Dormant |
| May | 3" | 4.1" | 0" | ✅ Rainfall sufficient |
| Jun | 3" | 3.4" | 0" | ✅ Rainfall sufficient |
| Jul | 3" | 4.1" | 0" | ✅ Rainfall sufficient |
| Aug | 3" | 4.1" | 0" | ✅ Rainfall sufficient |
| Sep | 3" | 3" | 0" | ✅ Rainfall sufficient |
| Oct | — | 3.4" | 0" | ❄️ Dormant |
| Nov | — | 2.7" | 0" | ❄️ Dormant |
| Dec | — | 3.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Franklin 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 — Franklin County, ME
Radicchio Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 2 | Apr 2 – Apr 16 |
| Transplant Outdoors | May 14 | May 14 – May 28 |
| Direct Sow | May 7 | May 7 – May 28 |
| Harvest | July 16 | Jul 16 – Aug 20 |
| Fall Sowing | July 6 | Jul 6 – Jul 20 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Fall Sowing Harvest |
| August | Harvest |
| September | — |
| 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 4a
📆 Growing Season
137 days in Franklin County
Growing Tips for Radicchio in Franklin County
Direct sow Radicchio outdoors after May 14 in Franklin County when soil has warmed and frost danger has passed.
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
Check more plant combinations with our Companion Planting Checker →
Radicchio in Other Locations
Frequently Asked Questions
When should I plant Radicchio in Franklin County, ME?
Franklin County is in Zone 4a with an average last frost of May 14. Plan your Radicchio planting based on this frost date — see the calendar above for exact timing.
What planting zone is Franklin County, ME?
Franklin County, Maine is in USDA Hardiness Zone 4a. The average last spring frost is May 14 and first fall frost is September 28.
Plan Your Garden with Confidence
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