When to Plant Endive in St. Clair County, IL
Endive is a leafy green with a slightly bitter flavor, available in curly (frisee) and broad-leaved (escarole) types. It adds texture and complexity to salads.
St. Clair County, Illinois is in USDA Zone 6b. The average last spring frost is April 2 and the first fall frost is November 2, giving you a growing season of approximately 214 days.
At an elevation of 711 feet, St. Clair County receives approximately 34.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Endive during the growing season.
St. Clair County Soil Profile
Soil Type
Silt Loam
Soil pH
6-7.3
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 St. Clair County
How your county's soil matches Endive's growing requirements.
Soil pH
Your soil pH (6.0–7.3) overlaps with Endive's range (5.5–7.0), though not a perfect match.
Soil Texture
The silt loam soil in St. Clair County is excellent for Endive — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.1%) — Endive will thrive.
How to Plant Endive
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Endive
Sow every 5.1 weeks. Last sowing by Aug 29 to harvest before frost.
For a dedicated fall crop, sow by Aug 24.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Endive
Endive needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.
| Month | Endive Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.5" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.5" | 0" | ❄️ Dormant |
| Apr | 3" | 3.2" | 0" | ✅ Rainfall sufficient |
| May | 3" | 3.8" | 0" | ✅ Rainfall sufficient |
| Jun | 3" | 4" | 0" | ✅ Rainfall sufficient |
| Jul | 3" | 3.8" | 0" | ✅ Rainfall sufficient |
| Aug | 3" | 3.9" | 0" | ✅ Rainfall sufficient |
| Sep | 3" | 3.3" | 0" | ✅ Rainfall sufficient |
| Oct | 3" | 2.5" | 0.5" | 💧 Light watering |
| Nov | 3" | 2.4" | 0.6" | 💧 Light watering |
| Dec | — | 1.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Nov in St. Clair County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Endive 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.
Endive Planting Timeline — St. Clair County, IL
Endive Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 26 | Feb 26 – Mar 12 |
| Transplant Outdoors | April 2 | Apr 2 – Apr 16 |
| Direct Sow | March 19 | Mar 19 – Apr 9 |
| Harvest | May 21 | May 21 – Jun 25 |
| Fall Sowing | August 24 | Aug 24 – Sep 7 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | Harvest |
| June | Harvest |
| July | — |
| August | Fall Sowing |
| September | Fall Sowing |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.7"/week · Only during dry spells
📅 Days to Maturity
45–65 days
🧪 Soil pH
Needs 5.5–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 6b
📆 Growing Season
214 days in St. Clair County
Growing Tips for Endive in St. Clair County
Direct sow Endive outdoors after April 02 in St. Clair County when soil has warmed and frost danger has passed.
Your generous 214.0-day season in St. Clair County allows multiple plantings of Endive. Sow every 22.0 days for continuous harvest.
Common pests for Endive in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.
General growing tips
Sow seeds directly in spring or fall. Blanch heads by tying outer leaves together 2-3 weeks before harvest to reduce bitterness. Keep soil evenly moist.
Companion Planting
Good Companions
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Endive in Other Locations
Frequently Asked Questions
When should I plant Endive in St. Clair County, IL?
St. Clair County is in Zone 6b with an average last frost of April 2. Plan your Endive planting based on this frost date — see the calendar above for exact timing.
What planting zone is St. Clair County, IL?
St. Clair County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 2 and first fall frost is November 2.
Plan Your Garden with Confidence
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