When to Plant Radicchio in Nevada County, CA
Your May gardening checklist
Your garden in Nevada County, California is working on a schedule, even when you're not. Here's where you should be this May.
-
Set out radicchio seedlings
Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.
June prep starts now
- Starting indoors: 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.
Nevada County, California is in USDA Zone 9a. The average last spring frost is May 10 and the first fall frost is October 22, giving you a growing season of approximately 165 days.
At an elevation of 2,745 feet, Nevada County receives approximately 44.7 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Radicchio to ensure they mature before fall.
Nevada County Soil Profile
Soil Type
Loam
Soil pH
6.8-7.5
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 Nevada County
How your county's soil matches Radicchio's growing requirements.
Soil pH
Your soil pH (6.8–7.5) is more alkaline than Radicchio prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Nevada County is excellent for Radicchio — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Radicchio.
Organic Matter
Organic matter is moderate (2.9%). Annual compost additions will help Radicchio.
How to Plant Radicchio
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Succession Planting Radicchio
Sow every 6.9 weeks. Last sowing by Aug 03 to harvest before frost.
For a dedicated fall crop, sow by Aug 27.
Plant Water Budget
Water stress score is 8/10 — 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 | — | 9.9" | 0" | ❄️ Dormant |
| Feb | — | 8.7" | 0" | ❄️ Dormant |
| Mar | — | 7.9" | 0" | ❄️ Dormant |
| Apr | — | 3" | 0" | ❄️ Dormant |
| May | 3" | 1.3" | 1.7" | 🚿 Regular watering |
| Jun | 3" | 0.2" | 2.8" | 🚿 Regular watering |
| Jul | 3" | 0" | 3" | 🚿 Regular watering |
| Aug | 3" | 0" | 3" | 🚿 Regular watering |
| Sep | 3" | 0.4" | 2.6" | 🚿 Regular watering |
| Oct | 3" | 1.9" | 1.1" | 💧 Light watering |
| Nov | — | 4.6" | 0" | ❄️ Dormant |
| Dec | — | 6.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Nevada 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 — Nevada County, CA
Radicchio Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 12 | Apr 12 – Apr 26 |
| Transplant Outdoors | May 10 | May 10 – May 24 |
| Direct Sow | April 19 | Apr 19 – May 10 |
| Harvest | July 12 | Jul 12 – Aug 16 |
| Fall Sowing | August 27 | Aug 27 – Sep 10 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Harvest |
| August | Fall Sowing Harvest |
| 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_alkaline
🗺️ USDA Zone
Zone 9a
📆 Growing Season
165 days in Nevada County
Growing Tips for Radicchio in Nevada County
Direct sow Radicchio outdoors after May 10 in Nevada 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 Nevada County, CA?
Nevada County is in Zone 9a with an average last frost of May 10. Plan your Radicchio planting based on this frost date — see the calendar above for exact timing.
What planting zone is Nevada County, CA?
Nevada County, California is in USDA Hardiness Zone 9a. The average last spring frost is May 10 and first fall frost is October 22.
Your Nevada County Garden Planner — Free
A 24-page printable planner built for Nevada County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.