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When to Plant Mizuna in Garfield County, WA

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.

Garfield County, Washington is in USDA Zone 6a. The average last spring frost is May 9 and the first fall frost is September 30, giving you a growing season of approximately 144 days.

At an elevation of 3,226 feet, Garfield County receives approximately 17.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88ยฐF, providing good warmth for Mizuna during the growing season. With low rainfall, drip irrigation is essential for growing Mizuna successfully. Mulch heavily to conserve soil moisture.

Garfield County, WA (Zone 6a) Short season
144 days
Last Spring Frost May 9
144 growing days
First Fall Frost September 30

Garfield County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.8

Drainage

Well Drained

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€” 2.7" 0" โ„๏ธ Dormant
Feb โ€” 2" 0" โ„๏ธ Dormant
Mar โ€” 1.7" 0" โ„๏ธ Dormant
Apr โ€” 1.1" 0" โ„๏ธ Dormant
May 4.3" 1.1" 3.2" ๐Ÿšฟ Regular watering
Jun 4.3" 0.6" 3.7" ๐Ÿšฟ Regular watering
Jul 4.3" 0.3" 4" ๐Ÿšฟ Regular watering
Aug 4.3" 0.3" 4" ๐Ÿšฟ Regular watering
Sep 4.3" 0.8" 3.5" ๐Ÿšฟ Regular watering
Oct โ€” 1.4" 0" โ„๏ธ Dormant
Nov โ€” 3" 0" โ„๏ธ Dormant
Dec โ€” 2.5" 0" โ„๏ธ Dormant

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

Mizuna Planting Timeline โ€” Garfield County, WA

Mizuna Planting Calendar

Activity When Date Range
Start Indoors April 4 Apr 4 โ€“ Apr 18
Transplant Outdoors May 9 May 9 โ€“ May 23
Direct Sow April 25 Apr 25 โ€“ May 16
Harvest June 13 Jun 13 โ€“ Jul 11
Fall Sowing July 22 Jul 22 โ€“ Aug 5

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

Moderate โ€” regular watering

๐Ÿ“… Days to Maturity

30โ€“45 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: N/A

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

144 days in Garfield County

Growing Tips for Garfield 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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Mizuna in Garfield County, WA?

Garfield County is in Zone 6a with an average last frost of May 9. Plan your Mizuna planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Garfield County, WA?

Garfield County, Washington is in USDA Hardiness Zone 6a. The average last spring frost is May 9 and first fall frost is September 30.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Garfield 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 Garfield County, WA. Local conditions may vary. Last updated: April 2026.