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When to Plant Tatsoi in San Joaquin County, CA

Tatsoi is a compact Asian green forming beautiful rosettes of dark, spoon-shaped leaves with a mild mustard flavor. It is extremely cold-hardy and versatile.

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 Tatsoi during the growing season. With low rainfall, drip irrigation is essential for growing Tatsoi 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 (245 days to spare)
Start indoors: Dec 21 Transplant: Jan 18 🍅 Harvest: Feb 22 – Mar 29
Recommended (50%) ✓ Fits season (235 days to spare)
Start indoors: Jan 7 Transplant: Feb 4 🍅 Harvest: Mar 11 – Apr 15
Safe Start (90%) ✓ Fits season (219 days to spare)
Start indoors: Feb 5 Transplant: Mar 5 🍅 Harvest: Apr 9 – May 14

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

Tatsoi needs ~839 GDD — county provides 6,043 GDD Excellent fit

Tatsoi Planting Timeline โ€” San Joaquin County, CA

Tatsoi Planting Calendar

Activity When Date Range
Start Indoors January 7 Jan 7 โ€“ Jan 21
Transplant Outdoors February 4 Feb 4 โ€“ Feb 18
Direct Sow January 14 Jan 14 โ€“ Feb 4
Fall Sowing October 11 Oct 11 โ€“ Oct 25
Harvest March 11 Mar 11 โ€“ Apr 15

Plant 0.5" deep ยท 6" apart ยท Rows 12" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors Direct Sow
February Transplant Outdoors Direct Sow
March Harvest
April Harvest
May โ€”
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

35โ€“50 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 9a

Growing Season

305 days

Growing Tips for San Joaquin County

Direct sow in spring or fall. Tatsoi tolerates frost down to 15F. Harvest outer leaves or cut whole rosettes. Excellent in salads, stir-fries, or lightly wilted.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Level Up Your Garden

Frequently Asked Questions

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

San Joaquin County is in Zone 9a with an average last frost of February 4. Plan your Tatsoi 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.

๐ŸŒฑ

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.