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When to Plant Tatsoi in Dane County, WI

Dane County, Wisconsin Zone 5b May

Top priorities for Dane County, Wisconsin gardeners in May

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

Avg. last frost April 30
Avg. first frost October 9
Soil temp (4") 58°F
Watering Low
Pest pressure Low
Daylight 14.5 hrs
Get ahead of June
  • 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.

Dane County, Wisconsin is in USDA Zone 5b. The average last spring frost is April 30 and the first fall frost is October 9, giving you a growing season of approximately 162 days.

At an elevation of 649 feet, Dane County receives approximately 38.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Tatsoi during the growing season.

Dane County, WI (Zone 5b) Moderate season
162 days
Last Spring Frost April 30
162 growing days
First Fall Frost October 9
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Dane County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (92 days to spare)
Start indoors: Mar 21 Transplant: Apr 25 🍅 Harvest: May 30 – Jul 4
Recommended (50%) ✓ Fits season (92 days to spare)
Start indoors: Mar 26 Transplant: Apr 30 🍅 Harvest: Jun 4 – Jul 9
Safe Start (90%) ✓ Fits season (88 days to spare)
Start indoors: Apr 16 Transplant: May 21 🍅 Harvest: Jun 25 – Jul 30

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 Dane County

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

Soil pH

Your soil pH (6.2–6.8) is within Tatsoi's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.5%) — 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

5
successive plantings in your 162-day season

Sow every 4 weeks. Last sowing by Aug 20 to harvest before frost.

For a dedicated fall crop, sow by Jul 31.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 1.8" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 4.3" 4" 0.3" 💧 Light watering
May 4.3" 4.5" 0" ✅ Rainfall sufficient
Jun 4.3" 4.3" 0" ✅ Rainfall sufficient
Jul 4.3" 4.8" 0" ✅ Rainfall sufficient
Aug 4.3" 3.7" 0.6" 💧 Light watering
Sep 4.3" 3.6" 0.7" 💧 Light watering
Oct 4.3" 2.7" 1.6" 💧 Light watering
Nov 2.9" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Dane 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 ~648 GDD — county provides 2,470 GDD Excellent fit

Tatsoi Planting Timeline — Dane County, WI

Tatsoi Planting Calendar

Activity When Date Range
Start Indoors March 26 Mar 26 – Apr 9
Transplant Outdoors April 30 Apr 30 – May 14
Direct Sow April 16 Apr 16 – May 7
Harvest June 4 Jun 4 – Jul 9
Fall Sowing July 31 Jul 31 – Aug 14

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
June Harvest
July Fall Sowing Harvest
August Fall Sowing
September
October
November
December
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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 5b

📆 Growing Season

162 days in Dane County

Growing Tips for Tatsoi in Dane County

Direct sow Tatsoi outdoors after April 30 in Dane County when soil has warmed and frost danger has passed.

Your generous 162.0-day season in Dane 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 Dane County, WI?

Dane County is in Zone 5b with an average last frost of April 30. Plan your Tatsoi planting based on this frost date — see the calendar above for exact timing.

What planting zone is Dane County, WI?

Dane County, Wisconsin is in USDA Hardiness Zone 5b. The average last spring frost is April 30 and first fall frost is October 9.

🌱

Your Dane County Garden Planner — Free

A 24-page printable planner built for Dane 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 Dane County, WI. 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.