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When to plant Zucchini in DeKalb County, IL

DeKalb County's climate puts the Zucchini spring window between April 29 and May 20. time plantings around the expected last-frost window for best survival.

When to Plant Zucchini in DeKalb County, IL

Zucchini

Zucchini is an incredibly prolific summer squash that can produce an abundance of fruit from just a few plants. It is versatile in the kitchen from grilling to baking.

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 Zucchini 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

How Much Zucchini to Grow

6-10 lbs
Average yield per plant
1
Plants per person
2 sq ft
Space per person

For a family of 4, plant approximately 4 zucchini plants in about 8 sq ft. In DeKalb County's 177-day season, you'll have plenty of time for a full harvest. Plan your garden layout →

Monthly Watering Guide for Zucchini

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

Month Zucchini 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.

Zucchini Planting Timeline — DeKalb County, IL

Zucchini Planting Calendar

Activity When Date Range
Start Indoors March 18 Mar 18 – Apr 1
Transplant Outdoors May 6 May 6 – May 20
Direct Sow April 29 Apr 29 – May 20
Harvest June 24 Jun 24 – Aug 19

Plant 1" deep · 30" apart · Rows 42" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

45–60 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 5b

📆 Growing Season

177 days in DeKalb County

Growing Tips for DeKalb County

Direct sow after last frost. Harvest when fruits are 6-8 inches long for best flavor and texture. Check plants daily in summer as fruits can double in size overnight.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Zucchini in DeKalb County, IL?

DeKalb County is in Zone 5b with an average last frost of April 22. Plan your Zucchini 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.

When should I plant Zucchini in DeKalb County, IL?

In DeKalb County, IL, plant Zucchini after the last frost (around April 22) and before the first frost (around October 16). Best results when soil holds above 50°F.

What growing zone is DeKalb County, IL for Zucchini?

DeKalb County sits in USDA Zone 5b. Zucchini grows reliably in zones 3a through 11b, so it's a good fit here.

Can Zucchini grow in DeKalb County's climate?

Yes — Zucchini grows well in DeKalb County's temperate climate. DeKalb County averages a 177-day frost-free season, with last frost around April 22 and first frost around October 16.

🌱

Your DeKalb County Garden Planner — Free

A 22-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.

Instant PDF download. No spam, unsubscribe any time.

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: August 2026.

Sources & credits

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