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When to Plant Tatsoi in Grant County, OR

Grant County, Oregon Zone 5b April

Your April game plan for Grant County, Oregon

We've pulled the most time-sensitive tasks for Grant County, Oregon this April and put them front and centre. Tackle them in order.

Avg. last frost June 6
Avg. first frost September 10
Soil temp (4") 36°F
Watering High
Pest pressure Low
Daylight 13.2 hrs
May prep starts now
  • Direct-sowing: tatsoi

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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.

Grant County, Oregon is in USDA Zone 5b. The average last spring frost is June 6 and the first fall frost is September 10, giving you a growing season of approximately 96 days.

At an elevation of 2,838 feet, Grant County receives approximately 22.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Tatsoi to ensure they mature before fall.

Grant County, OR (Zone 5b) Very short season
96 days
Last Spring Frost June 6
96 growing days
First Fall Frost September 10

Grant County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (18 days to spare)
Start indoors: Apr 15 Transplant: May 20 🍅 Harvest: Jun 24 – Jul 29
Recommended (50%) ✓ Fits season (26 days to spare)
Start indoors: May 2 Transplant: Jun 6 🍅 Harvest: Jul 11 – Aug 15
Safe Start (90%) ✓ Fits season (30 days to spare)
Start indoors: May 22 Transplant: Jun 26 🍅 Harvest: Jul 31 – Sep 4

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 Grant County

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

Soil pH

Your soil pH (5.4–6.4) is more acidic than Tatsoi prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Tatsoi.

Organic Matter

Organic matter is excellent (4.8%) — Tatsoi will thrive.

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

3
successive plantings in your 96-day season

Sow every 4 weeks. Last sowing by Jul 22 to harvest before frost.

For a dedicated fall crop, sow by Jul 02.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 266 gal / 100 sq ft

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 3.2" 0" ❄️ Dormant
Feb 2.9" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 1.5" 0" ❄️ Dormant
May 1.3" 0" ❄️ Dormant
Jun 4.3" 0.8" 3.5" 🚿 Regular watering
Jul 4.3" 0.4" 3.9" 🚿 Regular watering
Aug 4.3" 0.4" 3.9" 🚿 Regular watering
Sep 4.3" 0.9" 3.4" 🚿 Regular watering
Oct 1.8" 0" ❄️ Dormant
Nov 3.1" 0" ❄️ Dormant
Dec 3.9" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Grant 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 ~521 GDD — county provides 1,176 GDD Excellent fit

Tatsoi Planting Timeline — Grant County, OR

Tatsoi Planting Calendar

Activity When Date Range
Start Indoors May 2 May 2 – May 16
Transplant Outdoors June 6 Jun 6 – Jun 20
Direct Sow May 23 May 23 – Jun 13
Harvest July 11 Jul 11 – Aug 15
Fall Sowing July 2 Jul 2 – Jul 16

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

35–50 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 5b

📆 Growing Season

96 days in Grant County

Growing Tips for Tatsoi in Grant County

Direct sow Tatsoi outdoors after June 06 in Grant 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.

Grant County receives only 23" of rain annually. Tatsoi needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Grant County, OR?

Grant County is in Zone 5b with an average last frost of June 6. Plan your Tatsoi planting based on this frost date — see the calendar above for exact timing.

What planting zone is Grant County, OR?

Grant County, Oregon is in USDA Hardiness Zone 5b. The average last spring frost is June 6 and first fall frost is September 10.

🌱

Your Grant County Garden Planner — Free

A 24-page printable planner built for Grant County (Zone 5b). 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 Grant County, OR. Local conditions may vary. Last updated: April 2026.

Sources & credits

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