When to Plant Radicchio in Kings County, CA
Your May gardening checklist
Each item below is timed to Kings County, California's frost dates and soil temperatures. Skip nothing, stress about nothing.
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It's harvest week for radicchio
Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.
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.
Kings County, California is in USDA Zone 9a. The average last spring frost is February 14 and the first fall frost is December 2, giving you a growing season of approximately 291 days.
At an elevation of 2,065 feet, Kings County receives approximately 18.8 inches of rainfall annually with predominantly loam soil. Summer highs average 102°F, so Radicchio may need afternoon shade and extra watering during peak heat. With low rainfall, drip irrigation is essential for growing Radicchio successfully. Mulch heavily to conserve soil moisture.
Kings County Soil Profile
Soil Type
Loam
Soil pH
6.5-7.4
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 Kings County
How your county's soil matches Radicchio's growing requirements.
Soil pH
Your soil pH (6.5–7.4) overlaps with Radicchio's range (6.0–7.0), though not a perfect match.
Soil Texture
The loam soil in Kings County is excellent for Radicchio — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.1%). 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 Sep 13 to harvest before frost.
For a dedicated fall crop, sow by Oct 07.
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 | — | 3.6" | 0" | ❄️ Dormant |
| Feb | 3" | 4" | 0" | ✅ Rainfall sufficient |
| Mar | 3" | 3.2" | 0" | ✅ Rainfall sufficient |
| Apr | 3" | 1.4" | 1.6" | 🚿 Regular watering |
| May | 3" | 0.5" | 2.5" | 🚿 Regular watering |
| Jun | 3" | 0.1" | 2.9" | 🚿 Regular watering |
| Jul | 3" | 0" | 3" | 🚿 Regular watering |
| Aug | 3" | 0" | 3" | 🚿 Regular watering |
| Sep | 3" | 0.2" | 2.8" | 🚿 Regular watering |
| Oct | 3" | 0.7" | 2.3" | 🚿 Regular watering |
| Nov | 3" | 1.9" | 1.1" | 💧 Light watering |
| Dec | 3" | 3.2" | 0" | ✅ Rainfall sufficient |
Water needs are for active growing months only (Feb–Dec in Kings 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 — Kings County, CA
Radicchio Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 17 | Jan 17 – Jan 31 |
| Transplant Outdoors | February 14 | Feb 14 – Feb 28 |
| Direct Sow | January 24 | Jan 24 – Feb 14 |
| Harvest | April 18 | Apr 18 – May 23 |
| Fall Sowing | October 7 | Oct 7 – Oct 21 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors Direct Sow |
| February | Transplant Outdoors Direct Sow |
| March | — |
| April | Harvest |
| May | Harvest |
| June | — |
| July | — |
| August | — |
| September | — |
| October | Fall Sowing |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.7"/week · 1-2 times/week
📅 Days to Maturity
60–80 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 9a
📆 Growing Season
291 days in Kings County
Growing Tips for Radicchio in Kings County
Direct sow Radicchio outdoors after February 14 in Kings County when soil has warmed and frost danger has passed.
With summer highs reaching 102°F in Kings County, provide afternoon shade for Radicchio and water deeply in the morning.
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 Kings County, CA?
Kings County is in Zone 9a with an average last frost of February 14. Plan your Radicchio planting based on this frost date — see the calendar above for exact timing.
What planting zone is Kings County, CA?
Kings County, California is in USDA Hardiness Zone 9a. The average last spring frost is February 14 and first fall frost is December 2.
Your Kings County Garden Planner — Free
A 24-page printable planner built for Kings 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.