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When to plant Endive in Onarga, IL

Endive planted in Onarga between April 4 and April 25 matures in 45–65 days — well before the October 13 first frost. A second sowing from August 4 to August 18 extends the harvest into fall.

When to Plant Endive in Onarga, IL

Iroquois County, Illinois Zone 5b July

Top priorities for Iroquois County, Illinois gardeners in July

July is a pivotal month for Iroquois County, Illinois gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 18
Avg. first frost October 13
Soil temp (4") 74°F
Watering Moderate
Pest pressure High
Daylight 14.6 hrs
  1. Collect endive at their peak

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

Get ahead of August
  • Fall sowing: endive

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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.

Onarga, Illinois is in USDA Zone 5b. The average last spring frost is April 18 and the first fall frost is October 13, giving you a growing season of approximately 178 days.

At an elevation of 1,345 feet, Iroquois County receives approximately 30 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Endive during the growing season.

Onarga, IL (Zone 5b) Moderate season
178 days
Last Spring Frost April 18
178 growing days
First Fall Frost October 13

Onarga Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.7

Drainage

Well Drained

Endive Planting Risk Windows

Early Start (70% safe) ✓ Fits season (94 days to spare)
Start indoors: Mar 9 Transplant: Apr 13 🍅 Harvest: Jun 1 – Jul 6
Recommended (50%) ✓ Fits season (94 days to spare)
Start indoors: Mar 14 Transplant: Apr 18 🍅 Harvest: Jun 6 – Jul 11
Safe Start (90%) ✓ Fits season (92 days to spare)
Start indoors: Apr 1 Transplant: May 6 🍅 Harvest: Jun 24 – Jul 29

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 Onarga

How your county's soil matches Endive's growing requirements.

Soil pH

Your soil pH (5.9–6.7) is within Endive's preferred range (5.5–7.0).

Soil Texture

The silt loam soil in Iroquois County is excellent for Endive — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Endive.

Organic Matter

Organic matter is excellent (4.5%) — Endive will thrive.

How to Plant Endive

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Endive

4
successive plantings in your 178-day season

Sow every 5.1 weeks. Last sowing by Aug 09 to harvest before frost.

For a dedicated fall crop, sow by Aug 04.

Endive Water Budget

Plant needs
0.7″/week
Rainfall provides
0.7″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 384 gal / 100 sq ft
Drought risk

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 1.3" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 3" 2.8" 0.2" 💧 Light watering
May 3" 3.8" 0" ✅ Rainfall sufficient
Jun 3" 3.6" 0" ✅ Rainfall sufficient
Jul 3" 3" 0" ✅ Rainfall sufficient
Aug 3" 2.9" 0.1" 💧 Light watering
Sep 3" 3.2" 0" ✅ Rainfall sufficient
Oct 3" 2.5" 0.5" 💧 Light watering
Nov 2" 0" ❄️ Dormant
Dec 1.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Iroquois 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 needs ~756 GDD — county provides 2,447 GDD Excellent fit

Endive Planting Timeline — Onarga, IL

Endive Planting Calendar

Activity When Date Range
Start Indoors March 14 Mar 14 – Mar 28
Transplant Outdoors April 18 Apr 18 – May 2
Direct Sow April 4 Apr 4 – Apr 25
Harvest June 6 Jun 6 – Jul 11
Fall Sowing August 4 Aug 4 – Aug 18

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Transplant Outdoors Direct Sow
May Transplant Outdoors
June Harvest
July Harvest
August Fall Sowing
September
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: ideal

🗺️ USDA Zone

Zone 5b

📆 Growing Season

178 days in Iroquois County

Growing Tips for Endive in Onarga

Direct sow Endive outdoors after April 18 in Iroquois County when soil has warmed and frost danger has passed.

Your generous 178.0-day season in Iroquois 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

Avoid Planting Near

  • Fennel

Check more plant combinations with our Companion Planting Checker →

When should I plant Endive in Onarga, IL?

In Onarga, IL, plant Endive after the last frost (around April 18) and before the first frost (around October 13). Best results when soil holds above 50°F.

What growing zone is Onarga, IL for Endive?

Onarga sits in USDA Zone 5b. Endive grows reliably in zones 3a through 10b, so it's a good fit here.

Can Endive grow in Onarga's climate?

Yes — Endive grows well in Onarga's temperate climate. Onarga averages a 178-day frost-free season, with last frost around April 18 and first frost around October 13.

🌱

Your Iroquois County Garden Planner — Free

A 22-page printable planner built for Iroquois County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Iroquois County, IL. Local conditions may vary. Last updated: July 2026.