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When to Plant Sorrel in DeKalb County, IL

DeKalb County, Illinois Zone 5b May

May in DeKalb County, Illinois — your action list

Here's what deserves your attention in DeKalb County, Illinois this month. Everything below is tailored to Zone 5b and timed around your local frost dates.

Avg. last frost April 22
Avg. first frost October 16
Soil temp (4") 56°F
Watering Moderate
Pest pressure Low
Daylight 14.4 hrs
  1. Sow sorrel in trays indoors

    You're about 23 weeks out from your last frost — the perfect window to get these germinating indoors.

  2. Harvest sorrel as they ripen

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

A few tasks this May that'll pay off in June
  • 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.

DeKalb County, Illinois is in USDA Zone 5b. The average last spring frost is April 22 and the first fall frost is October 16, giving you a growing season of approximately 177 days.

At an elevation of 1,332 feet, DeKalb County receives approximately 34.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Sorrel during the growing season.

DeKalb County, IL (Zone 5b) Moderate season
177 days
Last Spring Frost April 22
177 growing days
First Fall Frost October 16

DeKalb County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (80 days to spare)
Start indoors: Mar 12 Transplant: Apr 9 🍅 Harvest: May 21 – Jul 23
Recommended (50%) ✓ Fits season (79 days to spare)
Start indoors: Mar 18 Transplant: Apr 15 🍅 Harvest: May 27 – Jul 29
Safe Start (90%) ✓ Fits season (76 days to spare)
Start indoors: Apr 4 Transplant: May 2 🍅 Harvest: Jun 13 – Aug 15

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 DeKalb County

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

Soil pH

Your soil pH (6.2–7.2) overlaps with Sorrel's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Sorrel.

Organic Matter

Organic matter is excellent (5.1%) — 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

5
successive plantings in your 177-day season

Sow every 4.6 weeks. Last sowing by Aug 17 to harvest before frost.

For a dedicated fall crop, sow by Aug 07.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 919 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 1.6" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 4.3" 3.1" 1.2" 💧 Light watering
May 4.3" 3.7" 0.6" 💧 Light watering
Jun 4.3" 4.4" 0" ✅ Rainfall sufficient
Jul 4.3" 3.9" 0.4" 💧 Light watering
Aug 4.3" 4.1" 0.2" 💧 Light watering
Sep 4.3" 3.1" 1.2" 💧 Light watering
Oct 4.3" 2.6" 1.7" 💧 Light watering
Nov 2.6" 0" ❄️ Dormant
Dec 1.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in DeKalb 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 ~762 GDD — county provides 2,699 GDD Excellent fit

Sorrel Planting Timeline — DeKalb County, IL

Sorrel Planting Calendar

Activity When Date Range
Start Indoors March 18 Mar 18 – Apr 1
Transplant Outdoors April 15 Apr 15 – Apr 29
Direct Sow April 8 Apr 8 – Apr 29
Harvest May 27 May 27 – Jul 29
Fall Sowing August 7 Aug 7 – Aug 21

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 Harvest
June Harvest
July Harvest
August Fall Sowing
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 5.5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 5b

📆 Growing Season

177 days in DeKalb County

Growing Tips for Sorrel in DeKalb County

Direct sow Sorrel outdoors after April 22 in DeKalb County when soil has warmed and frost danger has passed.

Your generous 177.0-day season in DeKalb 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 DeKalb County, IL?

DeKalb County is in Zone 5b with an average last frost of April 22. Plan your Sorrel planting based on this frost date — see the calendar above for exact timing.

What planting zone is DeKalb County, IL?

DeKalb County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 22 and first fall frost is October 16.

🌱

Your DeKalb County Garden Planner — Free

A 24-page printable planner built for DeKalb 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 DeKalb County, IL. 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.