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When to Plant Tatsoi in Clinton County, IL

Clinton County, Illinois Zone 6b May

May in the garden — Clinton County, Illinois

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

Avg. last frost April 10
Avg. first frost October 19
Soil temp (4") 63°F
Watering Low
Pest pressure Low
Daylight 14.1 hrs
  1. Fire up the seed-starting tray: tatsoi

    These need a head start before your last frost (April 10). Sow into cells now so you're ready to transplant in a few weeks.

  2. Collect tatsoi at their peak

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

June prep starts now
  • 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.

Clinton County, Illinois is in USDA Zone 6b. The average last spring frost is April 10 and the first fall frost is October 19, giving you a growing season of approximately 192 days.

At an elevation of 1,142 feet, Clinton County receives approximately 38.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Tatsoi during the growing season.

Clinton County, IL (Zone 6b) Moderate season
192 days
Last Spring Frost April 10
192 growing days
First Fall Frost October 19

Clinton County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (122 days to spare)
Start indoors: Feb 28 Transplant: Apr 4 🍅 Harvest: May 9 – Jun 13
Recommended (50%) ✓ Fits season (122 days to spare)
Start indoors: Mar 6 Transplant: Apr 10 🍅 Harvest: May 15 – Jun 19
Safe Start (90%) ✓ Fits season (124 days to spare)
Start indoors: Mar 15 Transplant: Apr 19 🍅 Harvest: May 24 – Jun 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 Clinton County

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

Soil pH

Your soil pH (6.0–7.0) is within Tatsoi's preferred range (6.0–7.5).

Soil Texture

The silt loam soil in Clinton 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

6
successive plantings in your 192-day season

Sow every 4 weeks. Last sowing by Aug 30 to harvest before frost.

For a dedicated fall crop, sow by Aug 10.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 342 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 1.6" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.9" 0" ❄️ Dormant
Apr 4.3" 3.5" 0.8" 💧 Light watering
May 4.3" 4.3" 0" ✅ Rainfall sufficient
Jun 4.3" 4.9" 0" ✅ Rainfall sufficient
Jul 4.3" 4.3" 0" ✅ Rainfall sufficient
Aug 4.3" 3.9" 0.4" 💧 Light watering
Sep 4.3" 3.4" 0.9" 💧 Light watering
Oct 4.3" 3.2" 1.1" 💧 Light watering
Nov 2.6" 0" ❄️ Dormant
Dec 1.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Clinton 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 ~584 GDD — county provides 2,640 GDD Excellent fit

Tatsoi Planting Timeline — Clinton County, IL

Tatsoi Planting Calendar

Activity When Date Range
Start Indoors March 6 Mar 6 – Mar 20
Transplant Outdoors April 10 Apr 10 – Apr 24
Direct Sow March 27 Mar 27 – Apr 17
Harvest May 15 May 15 – Jun 19
Fall Sowing August 10 Aug 10 – Aug 24

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

Month-by-Month Timeline

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

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: ideal

🗺️ USDA Zone

Zone 6b

📆 Growing Season

192 days in Clinton County

Growing Tips for Tatsoi in Clinton County

Direct sow Tatsoi outdoors after April 10 in Clinton County when soil has warmed and frost danger has passed.

Your generous 192.0-day season in Clinton 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 Clinton County, IL?

Clinton County is in Zone 6b with an average last frost of April 10. Plan your Tatsoi planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clinton County, IL?

Clinton County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 10 and first fall frost is October 19.

🌱

Your Clinton County Garden Planner — Free

A 24-page printable planner built for Clinton 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 Clinton County, IL. 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.