When to Plant Napa Cabbage in Ventura County, CA
May in the garden — Ventura County, California
If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.
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Basket week: napa cabbage
The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.
June prep starts now
- First harvests: napa cabbage
Napa cabbage forms tall, barrel-shaped heads with tender, crinkled leaves and a mild, slightly sweet flavor. It is the primary cabbage used for kimchi.
Ventura County, California is in USDA Zone 10a. The average last spring frost is March 18 and the first fall frost is November 15, giving you a growing season of approximately 242 days.
At an elevation of 2,094 feet, Ventura County receives approximately 19.4 inches of rainfall annually with predominantly loam soil. Summer highs average 88°F, providing good warmth for Napa Cabbage during the growing season. With low rainfall, drip irrigation is essential for growing Napa Cabbage successfully. Mulch heavily to conserve soil moisture.
Ventura County Soil Profile
Soil Type
Loam
Soil pH
6-7.7
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 Ventura County
How your county's soil matches Napa Cabbage's growing requirements.
Soil pH
Your soil pH (6.0–7.7) overlaps with Napa Cabbage's range (6.0–7.5), though not a perfect match.
Soil Texture
The loam soil in Ventura County is excellent for Napa Cabbage — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.3%). Annual compost additions will help Napa Cabbage.
How to Plant Napa Cabbage
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Succession Planting Napa Cabbage
Sow every 6.3 weeks. Last sowing by Sep 01 to harvest before frost.
For a dedicated fall crop, sow by Sep 20.
Plant Water Budget
Water stress score is 10/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Napa Cabbage
Napa Cabbage needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.
| Month | Napa Cabbage Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 3.8" | 0" | ❄️ Dormant |
| Feb | — | 4.4" | 0" | ❄️ Dormant |
| Mar | 6.5" | 3.2" | 3.3" | 🚿 Regular watering |
| Apr | 6.5" | 1.5" | 5" | 🚿 Regular watering |
| May | 6.5" | 0.6" | 5.9" | 🚿 Regular watering |
| Jun | 6.5" | 0.1" | 6.4" | 🚿 Regular watering |
| Jul | 6.5" | 0" | 6.5" | 🚿 Regular watering |
| Aug | 6.5" | 0" | 6.5" | 🚿 Regular watering |
| Sep | 6.5" | 0.2" | 6.3" | 🚿 Regular watering |
| Oct | 6.5" | 0.8" | 5.7" | 🚿 Regular watering |
| Nov | 6.5" | 1.7" | 4.8" | 🚿 Regular watering |
| Dec | — | 3.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Ventura County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Napa Cabbage 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.
Napa Cabbage Planting Timeline — Ventura County, CA
Napa Cabbage Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 18 | Feb 18 – Mar 4 |
| Transplant Outdoors | March 18 | Mar 18 – Apr 1 |
| Direct Sow | February 25 | Feb 25 – Mar 18 |
| Harvest | May 13 | May 13 – Jun 17 |
| Fall Sowing | September 20 | Sep 20 – Oct 4 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors Direct Sow |
| March | Start Indoors Transplant Outdoors Direct Sow |
| April | Transplant Outdoors |
| May | Harvest |
| June | Harvest |
| July | — |
| August | — |
| September | Fall Sowing |
| October | Fall Sowing |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1.5"/week · 2-3 times/week
📅 Days to Maturity
55–75 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 10a
📆 Growing Season
242 days in Ventura County
Growing Tips for Napa Cabbage in Ventura County
Direct sow Napa Cabbage outdoors after March 18 in Ventura County when soil has warmed and frost danger has passed.
Common pests for Napa Cabbage in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
Ventura County receives only 19" of rain annually. Napa Cabbage needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Best grown as a fall crop. Direct sow in late summer, 60-70 days before first frost. Keep soil evenly moist. Bolt-resistant varieties are available for spring planting.
Companion Planting
Good Companions
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Check more plant combinations with our Companion Planting Checker →
Napa Cabbage in Other Locations
Frequently Asked Questions
When should I plant Napa Cabbage in Ventura County, CA?
Ventura County is in Zone 10a with an average last frost of March 18. Plan your Napa Cabbage planting based on this frost date — see the calendar above for exact timing.
What planting zone is Ventura County, CA?
Ventura County, California is in USDA Hardiness Zone 10a. The average last spring frost is March 18 and first fall frost is November 15.
Your Ventura County Garden Planner — Free
A 24-page printable planner built for Ventura County (Zone 10a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.