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When to Plant Mache in Grant County, WA

Mache (corn salad) is a cold-hardy salad green with small, rounded, tender leaves and a mild, nutty flavor. It thrives in cool weather and even overwinters in many climates.

Grant County, Washington is in USDA Zone 6b. The average last spring frost is April 29 and the first fall frost is October 10, giving you a growing season of approximately 164 days.

At an elevation of 3,122 feet, Grant County receives approximately 17.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91ยฐF, providing good warmth for Mache during the growing season. With low rainfall, drip irrigation is essential for growing Mache successfully. Mulch heavily to conserve soil moisture.

Grant County, WA (Zone 6b) Moderate season
164 days
Last Spring Frost April 29
164 growing days
First Fall Frost October 10

Grant County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (93 days to spare)
Start indoors: Mar 10 Transplant: Apr 14 🍅 Harvest: May 26 – Jun 30
Recommended (50%) ✓ Fits season (87 days to spare)
Start indoors: Mar 25 Transplant: Apr 29 🍅 Harvest: Jun 10 – Jul 15
Safe Start (90%) ✓ Fits season (91 days to spare)
Start indoors: Apr 14 Transplant: May 19 🍅 Harvest: Jun 30 – Aug 4

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
0.5″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 802 gal / 100 sq ft
Mache needs ~912 GDD — county provides 2,993 GDD Excellent fit

Mache Planting Timeline โ€” Grant County, WA

Mache Planting Calendar

Activity When Date Range
Start Indoors March 25 Mar 25 โ€“ Apr 8
Transplant Outdoors April 29 Apr 29 โ€“ May 13
Direct Sow April 15 Apr 15 โ€“ May 6
Fall Sowing August 1 Aug 1 โ€“ Aug 15
Harvest June 10 Jun 10 โ€“ Jul 15

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 Direct Sow
June Harvest
July Harvest
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

40โ€“60 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 6b

Growing Season

164 days

Growing Tips for Grant County

Direct sow in early spring or late summer for fall and winter harvest. Seeds need light to germinate so press gently into soil surface. Harvest whole rosettes.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Mache in Grant County, WA?

Grant County is in Zone 6b with an average last frost of April 29. Plan your Mache planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Grant County, WA?

Grant County, Washington is in USDA Hardiness Zone 6b. The average last spring frost is April 29 and first fall frost is October 10.

๐ŸŒฑ

Plan Your Garden with Confidence

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