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When to plant Zucchini in Cook County, IL

Plant Zucchini in Cook County, when soil hits 50°F — usually April 30. Continue planting through May 21 for the spring crop.

When to Plant Zucchini in Cook 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.

Cook County, Illinois is in USDA Zone 6a. The average last spring frost is April 23 and the first fall frost is October 17, giving you a growing season of approximately 177 days.

At an elevation of 728 feet, Cook County receives approximately 35.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Zucchini during the growing season.

Cook County, IL (Zone 6a) Moderate season
177 days
Last Spring Frost April 23
177 growing days
First Fall Frost October 17

Cook County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7

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 Cook 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 1.5" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 4.3" 3.6" 0.7" 💧 Light watering
May 4.3" 4.1" 0.2" 💧 Light watering
Jun 4.3" 4.7" 0" ✅ Rainfall sufficient
Jul 4.3" 3.7" 0.6" 💧 Light watering
Aug 4.3" 3.2" 1.1" 💧 Light watering
Sep 4.3" 2.9" 1.4" 💧 Light watering
Oct 4.3" 3" 1.3" 💧 Light watering
Nov 2.3" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

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

Zucchini Planting Timeline — Cook County, IL

Zucchini Planting Calendar

Activity When Date Range
Start Indoors March 19 Mar 19 – Apr 2
Transplant Outdoors May 7 May 7 – May 21
Direct Sow April 30 Apr 30 – May 21
Harvest June 25 Jun 25 – Aug 20

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 6a

📆 Growing Season

177 days in Cook County

Growing Tips for Cook 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 Cook County, IL?

Cook County is in Zone 6a with an average last frost of April 23. Plan your Zucchini planting based on this frost date — see the calendar above for exact timing.

What planting zone is Cook County, IL?

Cook County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 23 and first fall frost is October 17.

When should I plant Zucchini in Cook County, IL?

In Cook County, IL, plant Zucchini after the last frost (around April 23) and before the first frost (around October 17). Best results when soil holds above 50°F.

What growing zone is Cook County, IL for Zucchini?

Cook County sits in USDA Zone 6a. Zucchini grows reliably in zones 3a through 11b, so it's a good fit here.

Can Zucchini grow in Cook County's climate?

Yes — Zucchini grows well in Cook County's temperate climate. Cook County averages a 177-day frost-free season, with last frost around April 23 and first frost around October 17.

🌱

Your Cook County Garden Planner — Free

A 22-page printable planner built for Cook 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.

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 Cook County, IL. Local conditions may vary. Last updated: July 2026.

Sources & credits

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