When to Plant Zucchini in Lake County, IL
May in Lake County, Illinois — your action list
May is a pivotal month for Lake County, Illinois gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Time to transplant zucchini
Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.
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Sow zucchini in trays indoors
You're about 21 weeks out from your last frost — the perfect window to get these germinating indoors.
A few tasks this May that'll pay off in June
- 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.
Lake County, Illinois is in USDA Zone 6a. The average last spring frost is April 21 and the first fall frost is October 20, giving you a growing season of approximately 182 days.
At an elevation of 1,080 feet, Lake County receives approximately 33.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Zucchini to ensure they mature before fall.
Lake County Soil Profile
Soil Type
Silt Loam
Soil pH
6.2-6.9
Drainage
Well Drained
Plant 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 Lake County
How your county's soil matches Zucchini's growing requirements.
Soil pH
Your soil pH (6.2–6.9) is within Zucchini's preferred range (6.0–7.5).
Soil Texture
The silt loam soil in Lake County is excellent for Zucchini — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.9%). Annual compost additions will help Zucchini.
How to Plant Zucchini
Succession Planting Zucchini
Sow every 5.1 weeks. Last sowing by Aug 21 to harvest before frost.
Plant 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 | — | 1.5" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 2" | 0" | ❄️ Dormant |
| Apr | 5.2" | 3.3" | 1.9" | 💧 Light watering |
| May | 5.2" | 3.9" | 1.3" | 💧 Light watering |
| Jun | 5.2" | 4.4" | 0.8" | 💧 Light watering |
| Jul | 5.2" | 3.3" | 1.9" | 💧 Light watering |
| Aug | 5.2" | 3.4" | 1.8" | 💧 Light watering |
| Sep | 5.2" | 3.3" | 1.9" | 💧 Light watering |
| Oct | 5.2" | 2.8" | 2.4" | 💧 Light watering |
| Nov | — | 2.3" | 0" | ❄️ Dormant |
| Dec | — | 1.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Lake 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 — Lake County, IL
Zucchini Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 17 | Mar 17 – Mar 31 |
| Transplant Outdoors | May 5 | May 5 – May 19 |
| Direct Sow | April 28 | Apr 28 – May 19 |
| Harvest | June 23 | Jun 23 – Aug 18 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | 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 6a
📆 Growing Season
182 days in Lake County
Growing Tips for Zucchini in Lake County
Direct sow Zucchini outdoors after April 21 in Lake County when soil has warmed and frost danger has passed.
Your generous 182.0-day season in Lake 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 Lake County, IL?
Lake County is in Zone 6a with an average last frost of April 21. Plan your Zucchini planting based on this frost date — see the calendar above for exact timing.
What planting zone is Lake County, IL?
Lake County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 21 and first fall frost is October 20.
Your Lake County Garden Planner — Free
A 24-page printable planner built for Lake 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.