When to plant Zucchini in Johnson County, IL
Plant Zucchini in Johnson County after April 7; the prime window is April 14–May 5.
When to Plant Zucchini in Johnson County, IL
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.
Johnson County, Illinois is in USDA Zone 7a. The average last spring frost is April 7 and the first fall frost is October 21, giving you a growing season of approximately 197 days.
At an elevation of 1,006 feet, Johnson County receives approximately 39.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Zucchini during the growing season.
Johnson County Soil Profile
Soil Type
Silt Loam
Soil pH
5.9-7.2
Drainage
Well Drained
How Much Zucchini to Grow
For a family of 4, plant approximately 4 zucchini plants in about 8 sq ft. In Johnson County's 197-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 | — | 1.9" | 0" | ❄️ Dormant |
| Mar | — | 2.9" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| May | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Jun | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.8" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.6" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 3.3" | 1" | 💧 Light watering |
| Oct | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Nov | — | 2.9" | 0" | ❄️ Dormant |
| Dec | — | 2.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Johnson County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Zucchini Planting Timeline — Johnson County, IL
Zucchini Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 10 | Mar 10 – Mar 24 |
| Transplant Outdoors | April 21 | Apr 21 – May 5 |
| Direct Sow | April 14 | Apr 14 – May 5 |
| Harvest | June 9 | Jun 9 – Aug 4 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Transplant Outdoors 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 7a
📆 Growing Season
197 days in Johnson County
Growing Tips for Johnson 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
Check more plant combinations with our Companion Planting Checker →
Zucchini in Other Locations
Frequently Asked Questions
When should I plant Zucchini in Johnson County, IL?
Johnson County is in Zone 7a with an average last frost of April 7. Plan your Zucchini planting based on this frost date — see the calendar above for exact timing.
What planting zone is Johnson County, IL?
Johnson County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 7 and first fall frost is October 21.
When should I plant Zucchini in Johnson County, IL?
In Johnson County, IL, plant Zucchini after the last frost (around April 7) and before the first frost (around October 21). Best results when soil holds above 50°F.
What growing zone is Johnson County, IL for Zucchini?
Johnson County sits in USDA Zone 7a. Zucchini grows reliably in zones 3a through 11b, so it's a good fit here.
Can Zucchini grow in Johnson County's climate?
Yes — Zucchini grows well in Johnson County's temperate climate. Johnson County averages a 197-day frost-free season, with last frost around April 7 and first frost around October 21.
Your Johnson County Garden Planner — Free
A 22-page printable planner built for Johnson County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.