When to plant Zucchini in Stephenson County County,
For Zucchini in Stephenson County County, the safe spring window opens around April 30 and closes around May 21. Last expected frost is April 23, first fall frost October 13, giving a 173-day growing season.
When to Plant Zucchini in Stephenson County, IL
June to-do list for Stephenson County, Illinois
Your Stephenson County, Illinois garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.
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Pick zucchini
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
July prep starts now
- First harvests: 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.
Stephenson County, Illinois is in USDA Zone 5a. The average last spring frost is April 23 and the first fall frost is October 13, giving you a growing season of approximately 173 days.
At an elevation of 1,345 feet, Stephenson County receives approximately 36.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Zucchini during the growing season.
Stephenson County Soil Profile
Soil Type
Silt Loam
Soil pH
6.2-7.1
Drainage
Well Drained
Zucchini Planting Risk Windows
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 Stephenson County
How your county's soil matches Zucchini's growing requirements.
Soil pH
Your soil pH (6.2–7.1) is within Zucchini's preferred range (6.0–7.5).
Soil Texture
The silt loam soil in Stephenson County is excellent for Zucchini — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.5%) — Zucchini will thrive.
How to Plant Zucchini
Succession Planting Zucchini
Sow every 5.1 weeks. Last sowing by Aug 14 to harvest before frost.
Zucchini Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Zucchini
Zucchini needs approximately 1.2 inches of water per week (5.2" per month). Here's how your county's rainfall compares month by month.
| Month | Zucchini Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.7" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.5" | 0" | ❄️ Dormant |
| Apr | 5.2" | 3.3" | 1.9" | 💧 Light watering |
| May | 5.2" | 4.7" | 0.5" | 💧 Light watering |
| Jun | 5.2" | 4" | 1.2" | 💧 Light watering |
| Jul | 5.2" | 4.1" | 1.1" | 💧 Light watering |
| Aug | 5.2" | 3.9" | 1.3" | 💧 Light watering |
| Sep | 5.2" | 3.5" | 1.7" | 💧 Light watering |
| Oct | 5.2" | 2.4" | 2.8" | 🚿 Regular watering |
| Nov | — | 2.3" | 0" | ❄️ Dormant |
| Dec | — | 2.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Stephenson County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Zucchini 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.
Zucchini Planting Timeline — Stephenson 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
| Month | Activities |
|---|---|
| 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
1.2"/week · 1-2 times/week
📅 Days to Maturity
45–60 days
🧪 Soil pH
Needs 6–7.5 · Your soil: ideal
🗺️ USDA Zone
Zone 5a
📆 Growing Season
173 days in Stephenson County
Growing Tips for Zucchini in Stephenson County
Direct sow Zucchini outdoors after April 23 in Stephenson County when soil has warmed and frost danger has passed.
Your generous 173.0-day season in Stephenson County allows multiple plantings of Zucchini. Sow every 22.0 days for continuous harvest.
Common pests for Zucchini in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
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 Stephenson County, IL?
Stephenson County is in Zone 5a 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 Stephenson County, IL?
Stephenson County, Illinois is in USDA Hardiness Zone 5a. The average last spring frost is April 23 and first fall frost is October 13.
When should I plant Zucchini in Stephenson County, ?
In Stephenson County, , plant Zucchini after the last frost (around April 23) and before the first frost (around October 13). Best results when soil holds above 50°F.
What growing zone is Stephenson County, for Zucchini?
Stephenson County sits in USDA Zone 5a. Zucchini grows reliably in zones 3a through 11b, so it's a good fit here.
Can Zucchini grow in Stephenson County's climate?
Yes — Zucchini grows well in Stephenson County's temperate climate. Stephenson County averages a 173-day frost-free season, with last frost around April 23 and first frost around October 13.
Your Stephenson County Garden Planner — Free
A 22-page printable planner built for Stephenson County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.