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When to Plant Tatsoi in Allegheny County, PA

Allegheny County, Pennsylvania Zone 6b May

This month in Allegheny County, Pennsylvania

May is a pivotal month for Allegheny County, Pennsylvania gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 25
Avg. first frost October 28
Soil temp (4") 62°F
Watering Moderate
Pest pressure Low
Daylight 14.2 hrs
  1. Begin indoor sowing: tatsoi

    Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.

  2. Collect tatsoi at their peak

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

Get ahead of June
  • 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.

Allegheny County, Pennsylvania is in USDA Zone 6b. The average last spring frost is April 25 and the first fall frost is October 28, giving you a growing season of approximately 186 days.

At an elevation of 118 feet, Allegheny County receives approximately 40.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Tatsoi during the growing season.

Allegheny County, PA (Zone 6b) Moderate season
186 days
Last Spring Frost April 25
186 growing days
First Fall Frost October 28
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Allegheny County Soil Profile

Soil Type

Silt Loam

Soil pH

5-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (112 days to spare)
Start indoors: Mar 15 Transplant: Apr 19 🍅 Harvest: May 24 – Jun 28
Recommended (50%) ✓ Fits season (116 days to spare)
Start indoors: Mar 21 Transplant: Apr 25 🍅 Harvest: May 30 – Jul 4
Safe Start (90%) ✓ Fits season (107 days to spare)
Start indoors: Apr 9 Transplant: May 14 🍅 Harvest: Jun 18 – Jul 23

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 Allegheny County

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

Soil pH

Your soil pH (5.0–6.5) is more acidic than Tatsoi prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.8%). 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

6
successive plantings in your 186-day season

Sow every 4 weeks. Last sowing by Sep 08 to harvest before frost.

For a dedicated fall crop, sow by Aug 19.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 145 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" 0" ❄️ Dormant
Feb 3.1" 0" ❄️ Dormant
Mar 3.7" 0" ❄️ Dormant
Apr 4.3" 3.2" 1.1" 💧 Light watering
May 4.3" 3.4" 0.9" 💧 Light watering
Jun 4.3" 3.5" 0.8" 💧 Light watering
Jul 4.3" 4.1" 0.2" 💧 Light watering
Aug 4.3" 3.6" 0.7" 💧 Light watering
Sep 4.3" 3" 1.3" 💧 Light watering
Oct 4.3" 3.8" 0.5" 💧 Light watering
Nov 2.9" 0" ❄️ Dormant
Dec 3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Allegheny 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 ~712 GDD — county provides 3,115 GDD Excellent fit

Tatsoi Planting Timeline — Allegheny County, PA

Tatsoi Planting Calendar

Activity When Date Range
Start Indoors March 21 Mar 21 – Apr 4
Transplant Outdoors April 25 Apr 25 – May 9
Direct Sow April 11 Apr 11 – May 2
Harvest May 30 May 30 – Jul 4
Fall Sowing August 19 Aug 19 – Sep 2

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

Month-by-Month Timeline

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

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

35–50 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 6b

📆 Growing Season

186 days in Allegheny County

Growing Tips for Tatsoi in Allegheny County

Direct sow Tatsoi outdoors after April 25 in Allegheny County when soil has warmed and frost danger has passed.

Your generous 186.0-day season in Allegheny 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.

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 Allegheny County, PA?

Allegheny County is in Zone 6b with an average last frost of April 25. Plan your Tatsoi planting based on this frost date — see the calendar above for exact timing.

What planting zone is Allegheny County, PA?

Allegheny County, Pennsylvania is in USDA Hardiness Zone 6b. The average last spring frost is April 25 and first fall frost is October 28.

🌱

Your Allegheny County Garden Planner — Free

A 24-page printable planner built for Allegheny County (Zone 6b). 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 Allegheny County, PA. 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.