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When to Plant Tatsoi in Weston County, WY

Weston County, Wyoming Zone 4b May

Top priorities for Weston County, Wyoming gardeners in May

Welcome to May in Zone 4b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost May 16
Avg. first frost September 26
Soil temp (4") 37°F
Watering High
Pest pressure Low
Daylight 14.5 hrs
  1. Plant out tatsoi

    Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.

  2. Scatter tatsoi into prepared beds

    These tolerate cool soil, so you're not gambling by sowing now.

Coming up in June — start thinking about
  • Starting indoors: tatsoi
  • First harvests: 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.

Weston County, Wyoming is in USDA Zone 4b. The average last spring frost is May 16 and the first fall frost is September 26, giving you a growing season of approximately 133 days.

At an elevation of 5,889 feet, Weston County receives approximately 20.7 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Tatsoi to ensure they mature before fall.

Weston County, WY (Zone 4b) Short season
133 days
Last Spring Frost May 16
133 growing days
First Fall Frost September 26

Weston County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (59 days to spare)
Start indoors: Mar 31 Transplant: May 12 🍅 Harvest: Jun 16 – Jul 21
Recommended (50%) ✓ Fits season (63 days to spare)
Start indoors: Apr 4 Transplant: May 16 🍅 Harvest: Jun 20 – Jul 25
Safe Start (90%) ✓ Fits season (66 days to spare)
Start indoors: Apr 17 Transplant: May 29 🍅 Harvest: Jul 3 – Aug 7

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 Weston County

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

Soil pH

Your soil pH (6.7–7.7) overlaps with Tatsoi's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help Tatsoi.

How to Plant Tatsoi

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

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Succession Planting Tatsoi

4
successive plantings in your 133-day season

Sow every 4 weeks. Last sowing by Aug 07 to harvest before frost.

For a dedicated fall crop, sow by Jul 04.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 492 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 1.5" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 2.3" 0" ❄️ Dormant
May 4.3" 2.3" 2" 💧 Light watering
Jun 4.3" 1.5" 2.8" 🚿 Regular watering
Jul 4.3" 1.9" 2.4" 🚿 Regular watering
Aug 4.3" 2.2" 2.1" 💧 Light watering
Sep 4.3" 1.6" 2.7" 🚿 Regular watering
Oct 1.9" 0" ❄️ Dormant
Nov 1.2" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Weston 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 ~457 GDD — county provides 1,429 GDD Excellent fit

Tatsoi Planting Timeline — Weston County, WY

Tatsoi Planting Calendar

Activity When Date Range
Start Indoors April 4 Apr 4 – Apr 18
Transplant Outdoors May 16 May 16 – May 30
Direct Sow May 9 May 9 – May 30
Harvest June 20 Jun 20 – Jul 25
Fall Sowing July 4 Jul 4 – Jul 18

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May Transplant Outdoors Direct Sow
June Harvest
July Fall Sowing Harvest
August
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: acceptable

🗺️ USDA Zone

Zone 4b

📆 Growing Season

133 days in Weston County

Growing Tips for Tatsoi in Weston County

Direct sow Tatsoi outdoors after May 16 in Weston County when soil has warmed and frost danger has passed.

Your generous 133.0-day season in Weston County allows multiple plantings of Tatsoi. Sow every 17.0 days for continuous harvest.

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

Weston County receives only 21" 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 Weston County, WY?

Weston County is in Zone 4b with an average last frost of May 16. Plan your Tatsoi planting based on this frost date — see the calendar above for exact timing.

What planting zone is Weston County, WY?

Weston County, Wyoming is in USDA Hardiness Zone 4b. The average last spring frost is May 16 and first fall frost is September 26.

🌱

Your Weston County Garden Planner — Free

A 24-page printable planner built for Weston County (Zone 4b). 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 Weston County, WY. 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.