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When to Plant Tatsoi in Lassen County, CA

Lassen County, California Zone 7a May

Your May game plan for Lassen County, California

A quick May briefing for Lassen County, California gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 28
Avg. first frost September 29
Soil temp (4") 58°F
Watering Critical
Pest pressure Low
Daylight 14.3 hrs
  1. Get tatsoi in the ground

    Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.

  2. Scatter tatsoi into prepared beds

    Keep the top inch of soil moist until germination — a gentle morning watering for 5–7 days does the job.

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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.

Lassen County, California is in USDA Zone 7a. The average last spring frost is May 28 and the first fall frost is September 29, giving you a growing season of approximately 124 days.

At an elevation of 1,854 feet, Lassen County receives approximately 43.7 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Tatsoi to ensure they mature before fall.

Lassen County, CA (Zone 7a) Short season
124 days
Last Spring Frost May 28
124 growing days
First Fall Frost September 29

Lassen County Soil Profile

Soil Type

Loam

Soil pH

6.1-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (52 days to spare)
Start indoors: Apr 13 Transplant: May 18 🍅 Harvest: Jun 22 – Jul 27
Recommended (50%) ✓ Fits season (54 days to spare)
Start indoors: Apr 23 Transplant: May 28 🍅 Harvest: Jul 2 – Aug 6
Safe Start (90%) ✓ Fits season (58 days to spare)
Start indoors: May 15 Transplant: Jun 19 🍅 Harvest: Jul 24 – Aug 28

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 Lassen County

How your county's soil matches Tatsoi's growing requirements.

Soil pH

Your soil pH (6.1–7.5) is within Tatsoi's preferred range (6.0–7.5).

Soil Texture

The loam soil in Lassen County is excellent for Tatsoi — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Tatsoi.

How to Plant Tatsoi

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Tatsoi

4
successive plantings in your 124-day season

Sow every 4 weeks. Last sowing by Aug 10 to harvest before frost.

For a dedicated fall crop, sow by Jul 21.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.5″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Tatsoi

Tatsoi needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Tatsoi Needs Rainfall You Supplement Action
Jan 9.2" 0" ❄️ Dormant
Feb 9.8" 0" ❄️ Dormant
Mar 7.7" 0" ❄️ Dormant
Apr 3.2" 0" ❄️ Dormant
May 4.3" 1" 3.3" 🚿 Regular watering
Jun 4.3" 0.2" 4.1" 🚿 Regular watering
Jul 4.3" 0" 4.3" 🚿 Regular watering
Aug 4.3" 0" 4.3" 🚿 Regular watering
Sep 4.3" 0.5" 3.8" 🚿 Regular watering
Oct 1.7" 0" ❄️ Dormant
Nov 3.9" 0" ❄️ Dormant
Dec 6.5" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Lassen County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Tatsoi 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.

Tatsoi needs ~552 GDD — county provides 1,612 GDD Excellent fit

Tatsoi Planting Timeline — Lassen County, CA

Tatsoi Planting Calendar

Activity When Date Range
Start Indoors April 23 Apr 23 – May 7
Transplant Outdoors May 28 May 28 – Jun 11
Direct Sow May 14 May 14 – Jun 4
Harvest July 2 Jul 2 – Aug 6
Fall Sowing July 21 Jul 21 – Aug 4

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

35–50 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 7a

📆 Growing Season

124 days in Lassen County

Growing Tips for Tatsoi in Lassen County

Direct sow Tatsoi outdoors after May 28 in Lassen County when soil has warmed and frost danger has passed.

Common pests for Tatsoi in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Tatsoi in Lassen County, CA?

Lassen County is in Zone 7a with an average last frost of May 28. Plan your Tatsoi planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lassen County, CA?

Lassen County, California is in USDA Hardiness Zone 7a. The average last spring frost is May 28 and first fall frost is September 29.

🌱

Your Lassen County Garden Planner — Free

A 24-page printable planner built for Lassen County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Lassen County, CA. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.