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When to Plant Chervil in San Joaquin County, CA

Chervil is a delicate herb with a subtle anise-parsley flavor, essential in French cuisine as part of fines herbes. It prefers cool conditions and partial shade.

San Joaquin County, California is in USDA Zone 9a. The average last spring frost is February 4 and the first fall frost is December 6, giving you a growing season of approximately 305 days.

At an elevation of 220 feet, San Joaquin County receives approximately 15 inches of rainfall annually with predominantly loam soil. Summer highs average 93ยฐF, providing good warmth for Chervil during the growing season. With low rainfall, drip irrigation is essential for growing Chervil successfully. Mulch heavily to conserve soil moisture.

San Joaquin County, CA (Zone 9a) Year-round
305 days
Last Spring Frost February 4
305 growing days
First Fall Frost December 6

San Joaquin County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (217 days to spare)
Start indoors: Dec 21 Transplant: Jan 11 🍅 Harvest: Feb 22 – Apr 26
Recommended (50%) ✓ Fits season (207 days to spare)
Start indoors: Jan 7 Transplant: Jan 28 🍅 Harvest: Mar 11 – May 13
Safe Start (90%) ✓ Fits season (191 days to spare)
Start indoors: Feb 5 Transplant: Feb 26 🍅 Harvest: Apr 9 – Jun 11

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.2″/week
You supply
1.0″/week
Watering frequency 2-3 times/week
Season total 2,595 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Chervil needs ~988 GDD — county provides 6,043 GDD Excellent fit

Chervil Planting Timeline โ€” San Joaquin County, CA

Chervil Planting Calendar

Activity When Date Range
Start Indoors January 7 Jan 7 โ€“ Jan 21
Transplant Outdoors January 28 Jan 28 โ€“ Feb 11
Direct Sow January 14 Jan 14 โ€“ Feb 4
Fall Sowing October 11 Oct 11 โ€“ Oct 25
Harvest March 11 Mar 11 โ€“ May 13

Plant 0.5" deep ยท 8" apart ยท Rows 12" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors Transplant Outdoors Direct Sow
February Transplant Outdoors Direct Sow
March Harvest
April Harvest
May Harvest
June โ€”
July โ€”
August โ€”
September โ€”
October Fall Sowing
November โ€”
December โ€”

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate โ€” regular watering

Days to Maturity

40โ€“60 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 9a

Growing Season

305 days

Growing Tips for San Joaquin County

Direct sow in early spring or fall as chervil bolts in heat. Provide shade and cool conditions. Harvest outer leaves as needed; use fresh as it loses flavor when dried.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Chervil in San Joaquin County, CA?

San Joaquin County is in Zone 9a with an average last frost of February 4. Plan your Chervil planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is San Joaquin County, CA?

San Joaquin County, California is in USDA Hardiness Zone 9a. The average last spring frost is February 4 and first fall frost is December 6.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help San Joaquin County gardeners in Zone 9a organize planting dates, track what's growing, and never miss a planting window.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for San Joaquin County, CA. Local conditions may vary. Last updated: April 2026.