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When to Plant Sorrel in Milwaukee County, WI

Milwaukee County, Wisconsin Zone 6a May

Top priorities for Milwaukee County, Wisconsin gardeners in May

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Milwaukee County, Wisconsin.

Avg. last frost April 27
Avg. first frost October 11
Soil temp (4") 56°F
Watering Low
Pest pressure Low
Daylight 14.5 hrs
Coming up in June — start thinking about
  • Starting indoors: sorrel
  • First harvests: sorrel

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Sorrel is a perennial herb with tangy, lemon-flavored arrow-shaped leaves. It is one of the first greens to emerge in spring and is used in soups and salads.

Milwaukee County, Wisconsin is in USDA Zone 6a. The average last spring frost is April 27 and the first fall frost is October 11, giving you a growing season of approximately 167 days.

At an elevation of 1,100 feet, Milwaukee County receives approximately 38.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Sorrel during the growing season.

Milwaukee County, WI (Zone 6a) Moderate season
167 days
Last Spring Frost April 27
167 growing days
First Fall Frost October 11

Milwaukee County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (68 days to spare)
Start indoors: Mar 18 Transplant: Apr 15 🍅 Harvest: May 27 – Jul 29
Recommended (50%) ✓ Fits season (69 days to spare)
Start indoors: Mar 23 Transplant: Apr 20 🍅 Harvest: Jun 1 – Aug 3
Safe Start (90%) ✓ Fits season (67 days to spare)
Start indoors: Apr 8 Transplant: May 6 🍅 Harvest: Jun 17 – Aug 19

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 Milwaukee County

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

Soil pH

Your soil pH (6.1–6.8) is within Sorrel's preferred range (5.5–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (5.0%) — Sorrel will thrive.

How to Plant Sorrel

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

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

Succession Planting Sorrel

4
successive plantings in your 167-day season

Sow every 4.6 weeks. Last sowing by Aug 12 to harvest before frost.

For a dedicated fall crop, sow by Aug 02.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 55 gal / 100 sq ft

Monthly Watering Guide for Sorrel

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

Month Sorrel Needs Rainfall You Supplement Action
Jan 1.7" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 4.3" 4.2" 0.1" 💧 Light watering
May 4.3" 4" 0.3" 💧 Light watering
Jun 4.3" 4.3" 0" ✅ Rainfall sufficient
Jul 4.3" 4.5" 0" ✅ Rainfall sufficient
Aug 4.3" 4" 0.3" 💧 Light watering
Sep 4.3" 3.2" 1.1" 💧 Light watering
Oct 4.3" 2.8" 1.5" 💧 Light watering
Nov 3" 0" ❄️ Dormant
Dec 2.3" 0" ❄️ Dormant

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

Sorrel 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.

Sorrel needs ~725 GDD — county provides 2,421 GDD Excellent fit

Sorrel Planting Timeline — Milwaukee County, WI

Sorrel Planting Calendar

Activity When Date Range
Start Indoors March 23 Mar 23 – Apr 6
Transplant Outdoors April 20 Apr 20 – May 4
Direct Sow April 13 Apr 13 – May 4
Harvest June 1 Jun 1 – Aug 3
Fall Sowing August 2 Aug 2 – Aug 16

Plant 0.5" deep · 8" 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 Harvest
September
October
November
December

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 5.5–7 · Your soil: ideal

🗺️ USDA Zone

Zone 6a

📆 Growing Season

167 days in Milwaukee County

Growing Tips for Sorrel in Milwaukee County

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

Your generous 167.0-day season in Milwaukee County allows multiple plantings of Sorrel. Sow every 20.0 days for continuous harvest.

General growing tips

Direct sow in early spring or fall. Remove flower stalks promptly to encourage leaf production. Divide clumps every 3-4 years. Young leaves have the best flavor.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sorrel in Milwaukee County, WI?

Milwaukee County is in Zone 6a with an average last frost of April 27. Plan your Sorrel planting based on this frost date — see the calendar above for exact timing.

What planting zone is Milwaukee County, WI?

Milwaukee County, Wisconsin is in USDA Hardiness Zone 6a. The average last spring frost is April 27 and first fall frost is October 11.

🌱

Your Milwaukee County Garden Planner — Free

A 24-page printable planner built for Milwaukee County (Zone 6a). 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 Milwaukee 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.