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When to Plant Mache in Olmsted County, MN

Olmsted County, Minnesota Zone 4b May

Olmsted County, Minnesota gardeners: here's your May plan

We've pulled the most time-sensitive tasks for Olmsted County, Minnesota this May and put them front and centre. Tackle them in order.

Avg. last frost May 3
Avg. first frost October 4
Soil temp (4") 53°F
Watering Moderate
Pest pressure Low
Daylight 14.6 hrs
  1. Time to transplant mache

    Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.

A few tasks this May that'll pay off in June
  • Starting indoors: mache
  • First harvests: mache

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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.

Olmsted County, Minnesota is in USDA Zone 4b. The average last spring frost is May 3 and the first fall frost is October 4, giving you a growing season of approximately 154 days.

At an elevation of 992 feet, Olmsted County receives approximately 32.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Mache to ensure they mature before fall.

Olmsted County, MN (Zone 4b) Moderate season
154 days
Last Spring Frost May 3
154 growing days
First Fall Frost October 4

Olmsted County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (77 days to spare)
Start indoors: Mar 15 Transplant: Apr 26 🍅 Harvest: Jun 7 – Jul 12
Recommended (50%) ✓ Fits season (77 days to spare)
Start indoors: Mar 22 Transplant: May 3 🍅 Harvest: Jun 14 – Jul 19
Safe Start (90%) ✓ Fits season (74 days to spare)
Start indoors: Apr 6 Transplant: May 18 🍅 Harvest: Jun 29 – Aug 3

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 Olmsted County

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

Soil pH

Your soil pH (5.9–7.3) overlaps with Mache's range (6.0–7.5), though not a perfect match.

Soil Texture

The silt loam soil in Olmsted County is excellent for Mache — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Mache.

Organic Matter

Organic matter is moderate (3.8%). Annual compost additions will help Mache.

How to Plant Mache

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Succession Planting Mache

4
successive plantings in your 154-day season

Sow every 4.6 weeks. Last sowing by Aug 05 to harvest before frost.

For a dedicated fall crop, sow by Jul 12.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 556 gal / 100 sq ft

Monthly Watering Guide for Mache

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

Month Mache Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 2" 0" ❄️ Dormant
Apr 2.9" 0" ❄️ Dormant
May 4.3" 3.5" 0.8" 💧 Light watering
Jun 4.3" 4.5" 0" ✅ Rainfall sufficient
Jul 4.3" 3.8" 0.5" 💧 Light watering
Aug 4.3" 3.4" 0.9" 💧 Light watering
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 2.4" 1.9" 💧 Light watering
Nov 2.6" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Olmsted County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Mache 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" — every day above 50°F 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.

Mache needs ~538 GDD — county provides 1,655 GDD Excellent fit

Mache Planting Timeline — Olmsted County, MN

Mache Planting Calendar

Activity When Date Range
Start Indoors March 22 Mar 22 – Apr 5
Transplant Outdoors May 3 May 3 – May 17
Direct Sow April 26 Apr 26 – May 17
Harvest June 14 Jun 14 – Jul 19
Fall Sowing July 12 Jul 12 – Jul 26

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 4b

📆 Growing Season

154 days in Olmsted County

Growing Tips for Mache in Olmsted County

Direct sow Mache outdoors after May 03 in Olmsted County when soil has warmed and frost danger has passed.

Your generous 154.0-day season in Olmsted County allows multiple plantings of Mache. Sow every 20.0 days for continuous harvest.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Mache in Olmsted County, MN?

Olmsted County is in Zone 4b with an average last frost of May 3. Plan your Mache planting based on this frost date — see the calendar above for exact timing.

What planting zone is Olmsted County, MN?

Olmsted County, Minnesota is in USDA Hardiness Zone 4b. The average last spring frost is May 3 and first fall frost is October 4.

🌱

Your Olmsted County Garden Planner — Free

A 24-page printable planner built for Olmsted County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Olmsted County, MN. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.