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When to Plant Mache in Penobscot County, ME

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.

Penobscot County, Maine is in USDA Zone 4b. The average last spring frost is May 10 and the first fall frost is October 2, giving you a growing season of approximately 145 days.

At an elevation of 842 feet, Penobscot County receives approximately 38.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Mache to ensure they mature before fall.

Penobscot County, ME (Zone 4b) Short season
145 days
Last Spring Frost May 10
145 growing days
First Fall Frost October 2

Penobscot County Soil Profile

Soil Type

Silt Loam

Soil pH

4.8-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (66 days to spare)
Start indoors: Mar 26 Transplant: May 7 🍅 Harvest: Jun 18 – Jul 23
Recommended (50%) ✓ Fits season (68 days to spare)
Start indoors: Mar 29 Transplant: May 10 🍅 Harvest: Jun 21 – Jul 26
Safe Start (90%) ✓ Fits season (71 days to spare)
Start indoors: Apr 13 Transplant: May 25 🍅 Harvest: Jul 6 – Aug 10

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
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Mache needs ~612 GDD — county provides 1,776 GDD Excellent fit

Mache Planting Timeline โ€” Penobscot County, ME

Mache Planting Calendar

Activity When Date Range
Start Indoors March 29 Mar 29 โ€“ Apr 12
Transplant Outdoors May 10 May 10 โ€“ May 24
Direct Sow May 3 May 3 โ€“ May 24
Fall Sowing July 10 Jul 10 โ€“ Jul 24
Harvest June 21 Jun 21 โ€“ Jul 26

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
May Transplant Outdoors Direct Sow
June Harvest
July Fall Sowing Harvest
August โ€”
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 4b

Growing Season

145 days

Growing Tips for Penobscot 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 Penobscot County, ME?

Penobscot County is in Zone 4b with an average last frost of May 10. Plan your Mache planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Penobscot County, ME?

Penobscot County, Maine is in USDA Hardiness Zone 4b. The average last spring frost is May 10 and first fall frost is October 2.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Penobscot County gardeners in Zone 4b organize planting dates, track what's growing, and never miss a planting window.

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Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Penobscot County, ME. Local conditions may vary. Last updated: April 2026.