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When to Plant Mache in Jefferson County, WI

Jefferson County, Wisconsin Zone 5b May

May in the garden — Jefferson County, Wisconsin

Welcome to May in Zone 5b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 27
Avg. first frost October 12
Soil temp (4") 60°F
Watering Low
Pest pressure Low
Daylight 14.5 hrs
June prep starts now
  • 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.

Jefferson County, Wisconsin is in USDA Zone 5b. The average last spring frost is April 27 and the first fall frost is October 12, giving you a growing season of approximately 168 days.

At an elevation of 613 feet, Jefferson County receives approximately 36.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Mache during the growing season.

Jefferson County, WI (Zone 5b) Moderate season
168 days
Last Spring Frost April 27
168 growing days
First Fall Frost October 12
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Jefferson County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (90 days to spare)
Start indoors: Mar 19 Transplant: Apr 23 🍅 Harvest: Jun 4 – Jul 9
Recommended (50%) ✓ Fits season (91 days to spare)
Start indoors: Mar 23 Transplant: Apr 27 🍅 Harvest: Jun 8 – Jul 13
Safe Start (90%) ✓ Fits season (89 days to spare)
Start indoors: Apr 8 Transplant: May 13 🍅 Harvest: Jun 24 – Jul 29

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 Jefferson County

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

Soil pH

Your soil pH (6.3–6.7) is within Mache's preferred range (6.0–7.5).

Soil Texture

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

Drainage

Drainage is adequate for Mache.

Organic Matter

Organic matter is excellent (4.1%) — Mache will thrive.

How to Plant Mache

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Mache

5
successive plantings in your 168-day season

Sow every 4.6 weeks. Last sowing by Aug 13 to harvest before frost.

For a dedicated fall crop, sow by Aug 03.

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 564 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 1.7" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 4.3" 2.9" 1.4" 💧 Light watering
May 4.3" 4.6" 0" ✅ Rainfall sufficient
Jun 4.3" 4.4" 0" ✅ Rainfall sufficient
Jul 4.3" 3.9" 0.4" 💧 Light watering
Aug 4.3" 4.2" 0.1" 💧 Light watering
Sep 4.3" 3.6" 0.7" 💧 Light watering
Oct 4.3" 2.7" 1.6" 💧 Light watering
Nov 2.7" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Jefferson 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 ~762 GDD — county provides 2,562 GDD Excellent fit

Mache Planting Timeline — Jefferson County, WI

Mache Planting Calendar

Activity When Date Range
Start Indoors March 23 Mar 23 – Apr 6
Transplant Outdoors April 27 Apr 27 – May 11
Direct Sow April 13 Apr 13 – May 4
Harvest June 8 Jun 8 – Jul 13
Fall Sowing August 3 Aug 3 – Aug 17

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 5b

📆 Growing Season

168 days in Jefferson County

Growing Tips for Mache in Jefferson County

Direct sow Mache outdoors after April 27 in Jefferson County when soil has warmed and frost danger has passed.

Your generous 168.0-day season in Jefferson 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 Jefferson County, WI?

Jefferson County is in Zone 5b with an average last frost of April 27. Plan your Mache planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jefferson County, WI?

Jefferson County, Wisconsin is in USDA Hardiness Zone 5b. The average last spring frost is April 27 and first fall frost is October 12.

🌱

Your Jefferson County Garden Planner — Free

A 24-page printable planner built for Jefferson County (Zone 5b). 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 Jefferson County, WI. 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.