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When to Plant Tatsoi in San Luis Obispo 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 Luis Obispo County, California is in USDA Zone 9b. The average last spring frost is March 23 and the first fall frost is November 9, giving you a growing season of approximately 231 days.

At an elevation of 2,412 feet, San Luis Obispo County receives approximately 18.4 inches of rainfall annually with predominantly loam soil. Summer highs average 98ยฐF, so Tatsoi may need afternoon shade and extra watering during peak heat. With low rainfall, drip irrigation is essential for growing Tatsoi successfully. Mulch heavily to conserve soil moisture.

San Luis Obispo County, CA (Zone 9b) Long season
231 days
Last Spring Frost March 23
231 growing days
First Fall Frost November 9

San Luis Obispo County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (171 days to spare)
Start indoors: Feb 5 Transplant: Mar 5 🍅 Harvest: Apr 9 – May 14
Recommended (50%) ✓ Fits season (161 days to spare)
Start indoors: Feb 23 Transplant: Mar 23 🍅 Harvest: Apr 27 – Jun 1
Safe Start (90%) ✓ Fits season (159 days to spare)
Start indoors: Mar 19 Transplant: Apr 16 🍅 Harvest: May 21 – Jun 25

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
0.3″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,642 gal / 100 sq ft
Drought risk

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

Tatsoi needs ~999 GDD — county provides 5,428 GDD Excellent fit

Tatsoi Planting Timeline โ€” San Luis Obispo County, CA

Tatsoi Planting Calendar

Activity When Date Range
Start Indoors February 23 Feb 23 โ€“ Mar 9
Transplant Outdoors March 23 Mar 23 โ€“ Apr 6
Direct Sow March 2 Mar 2 โ€“ Mar 23
Fall Sowing September 14 Sep 14 โ€“ Sep 28
Harvest April 27 Apr 27 โ€“ Jun 1

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March Start Indoors Transplant Outdoors Direct Sow
April Transplant Outdoors Harvest
May Harvest
June Harvest
July โ€”
August โ€”
September Fall Sowing
October โ€”
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 9b

Growing Season

231 days

Growing Tips for San Luis Obispo 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 Luis Obispo County, CA?

San Luis Obispo County is in Zone 9b with an average last frost of March 23. Plan your Tatsoi planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is San Luis Obispo County, CA?

San Luis Obispo County, California is in USDA Hardiness Zone 9b. The average last spring frost is March 23 and first fall frost is November 9.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help San Luis Obispo County gardeners in Zone 9b 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 Luis Obispo County, CA. Local conditions may vary. Last updated: April 2026.