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When to Plant Mizuna in Warren County, MO

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.

Warren County, Missouri is in USDA Zone 6a. The average last spring frost is April 11 and the first fall frost is October 25, giving you a growing season of approximately 197 days.

At an elevation of 654 feet, Warren County receives approximately 30 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89ยฐF, providing good warmth for Mizuna during the growing season.

Warren County, MO (Zone 6a) Moderate season
197 days
Last Spring Frost April 11
197 growing days
First Fall Frost October 25

Warren County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (132 days to spare)
Start indoors: Mar 1 Transplant: Apr 5 🍅 Harvest: May 10 – Jun 7
Recommended (50%) ✓ Fits season (134 days to spare)
Start indoors: Mar 7 Transplant: Apr 11 🍅 Harvest: May 16 – Jun 13
Safe Start (90%) ✓ Fits season (133 days to spare)
Start indoors: Mar 19 Transplant: Apr 23 🍅 Harvest: May 28 – Jun 25

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 632 gal / 100 sq ft
Mizuna needs ~628 GDD — county provides 3,299 GDD Excellent fit

Mizuna Planting Timeline โ€” Warren County, MO

Mizuna Planting Calendar

Activity When Date Range
Start Indoors March 7 Mar 7 โ€“ Mar 21
Transplant Outdoors April 11 Apr 11 โ€“ Apr 25
Direct Sow March 28 Mar 28 โ€“ Apr 18
Fall Sowing August 16 Aug 16 โ€“ Aug 30
Harvest May 16 May 16 โ€“ Jun 13

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate โ€” regular watering

Days to Maturity

30โ€“45 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 6a

Growing Season

197 days

Growing Tips for Warren County

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

Level Up Your Garden

Frequently Asked Questions

When should I plant Mizuna in Warren County, MO?

Warren County is in Zone 6a with an average last frost of April 11. Plan your Mizuna planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Warren County, MO?

Warren County, Missouri is in USDA Hardiness Zone 6a. The average last spring frost is April 11 and first fall frost is October 25.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Warren County gardeners in Zone 6a 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 Warren County, MO. Local conditions may vary. Last updated: April 2026.