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When to Plant Mizuna in Lee County, IL

Mizuna is a mild-flavored Japanese mustard green with feathery, deeply serrated leaves. It is fast-growing and makes an excellent addition to salads and stir-fries.

Lee County, Illinois is in USDA Zone 5a. The average last spring frost is April 22 and the first fall frost is October 14, giving you a growing season of approximately 175 days.

At an elevation of 1,010 feet, Lee County receives approximately 33.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Mizuna to ensure they mature before fall.

Lee County, IL (Zone 5a) Moderate season
175 days
Last Spring Frost April 22
175 growing days
First Fall Frost October 14

Lee County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (113 days to spare)
Start indoors: Mar 13 Transplant: Apr 17 🍅 Harvest: May 22 – Jun 19
Recommended (50%) ✓ Fits season (112 days to spare)
Start indoors: Mar 18 Transplant: Apr 22 🍅 Harvest: May 27 – Jun 24
Safe Start (90%) ✓ Fits season (113 days to spare)
Start indoors: Mar 31 Transplant: May 5 🍅 Harvest: Jun 9 – Jul 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 Lee County

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

Soil pH

Your soil pH (6.3โ€“6.9) is within Mizuna's preferred range (6.0โ€“7.5).

Soil Texture

The silt loam soil in Lee County is excellent for Mizuna โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Mizuna.

Organic Matter

Organic matter is excellent (4.8%) โ€” Mizuna will thrive.

How to Plant Mizuna

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 Mizuna

7
successive plantings in your 175-day season

Sow every 3.4 weeks. Last sowing by Aug 30 to harvest before frost.

For a dedicated fall crop, sow by Aug 05.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 923 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Mizuna

Mizuna needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Mizuna Needs Rainfall You Supplement Action
Jan โ€” 1.6" 0" โ„๏ธ Dormant
Feb โ€” 1.6" 0" โ„๏ธ Dormant
Mar โ€” 2" 0" โ„๏ธ Dormant
Apr 4.3" 2.8" 1.5" ๐Ÿ’ง Light watering
May 4.3" 4.4" 0" โœ… Rainfall sufficient
Jun 4.3" 4.2" 0.1" ๐Ÿ’ง Light watering
Jul 4.3" 3.3" 1" ๐Ÿ’ง Light watering
Aug 4.3" 3.5" 0.8" ๐Ÿ’ง Light watering
Sep 4.3" 2.9" 1.4" ๐Ÿ’ง Light watering
Oct 4.3" 2.7" 1.6" ๐Ÿ’ง Light watering
Nov โ€” 2.7" 0" โ„๏ธ Dormant
Dec โ€” 1.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Lee County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Mizuna 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" โ€” every day above 50ยฐF 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.

Mizuna needs ~488 GDD — county provides 2,275 GDD Excellent fit

Mizuna Planting Timeline โ€” Lee County, IL

Mizuna Planting Calendar

Activity When Date Range
Start Indoors March 18 Mar 18 โ€“ Apr 1
Transplant Outdoors April 22 Apr 22 โ€“ May 6
Direct Sow April 8 Apr 8 โ€“ Apr 29
Harvest May 27 May 27 โ€“ Jun 24
Fall Sowing August 5 Aug 5 โ€“ Aug 19

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

1"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

30โ€“45 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 5a

๐Ÿ“† Growing Season

175 days in Lee County

Growing Tips for Mizuna in Lee County

Direct sow Mizuna outdoors after April 22 in Lee County when soil has warmed and frost danger has passed.

Your generous 175.0-day season in Lee County allows multiple plantings of Mizuna. Sow every 15.0 days for continuous harvest.

Common pests for Mizuna 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. Harvest outer leaves as needed for a cut-and-come-again approach. Mizuna is one of the most cold-tolerant Asian greens.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Mizuna in Lee County, IL?

Lee County is in Zone 5a with an average last frost of April 22. Plan your Mizuna planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Lee County, IL?

Lee County, Illinois is in USDA Hardiness Zone 5a. The average last spring frost is April 22 and first fall frost is October 14.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Lee County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.

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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 Lee County, IL. Local conditions may vary. Last updated: April 2026.