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When to plant Belgian Endive in Knox County County,

For Knox County County, gardeners: plant Belgian Endive April 3 through April 24 once soil reads 50°F. A second sowing from August 6 to August 20 extends the harvest into fall.

When to Plant Belgian Endive in Knox County, IL

Knox County, Illinois Zone 5b June

This month in Knox County, Illinois

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Knox County, Illinois.

Avg. last frost April 17
Avg. first frost October 15
Soil temp (4") 67°F
Watering Moderate
Pest pressure High
Daylight 14.9 hrs

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Belgian endive is produced by forcing chicory roots in darkness to create tight, pale, torpedo-shaped heads called chicons. They have a mild bitterness and elegant crunch.

Knox County, Illinois is in USDA Zone 5b. The average last spring frost is April 17 and the first fall frost is October 15, giving you a growing season of approximately 181 days.

At an elevation of 1,301 feet, Knox County receives approximately 33.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Belgian Endive to ensure they mature before fall.

Knox County, IL (Zone 5b) Moderate season
181 days
Last Spring Frost April 17
181 growing days
First Fall Frost October 15
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Knox County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.8

Drainage

Well Drained

Belgian Endive Planting Risk Windows

Early Start (70% safe) ✓ Fits season (13 days to spare)
Start indoors: Mar 8 Transplant: Apr 12 🍅 Harvest: Aug 2 – Sep 27
Recommended (50%) ✓ Fits season (13 days to spare)
Start indoors: Mar 13 Transplant: Apr 17 🍅 Harvest: Aug 7 – Oct 2
Safe Start (90%) ✓ Fits season (17 days to spare)
Start indoors: Mar 29 Transplant: May 3 🍅 Harvest: Aug 23 – Oct 18

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 Knox County

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

Soil pH

Your soil pH (6.0–6.8) is within Belgian Endive's preferred range (5.5–7.0).

Soil Texture

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

Organic Matter

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

How to Plant Belgian 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.

Belgian Endive Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 444 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Belgian Endive

Belgian Endive needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Belgian Endive Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 4.3" 3.4" 0.9" 💧 Light watering
May 4.3" 3.9" 0.4" 💧 Light watering
Jun 4.3" 3.6" 0.7" 💧 Light watering
Jul 4.3" 4.1" 0.2" 💧 Light watering
Aug 4.3" 3.5" 0.8" 💧 Light watering
Sep 4.3" 2.6" 1.7" 💧 Light watering
Oct 4.3" 2.7" 1.6" 💧 Light watering
Nov 2.5" 0" ❄️ Dormant
Dec 1.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Knox County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Belgian 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.

Belgian Endive needs ~1,690 GDD — county provides 2,353 GDD Excellent fit

Belgian Endive Planting Timeline — Knox County, IL

Belgian Endive Planting Calendar

Activity When Date Range
Start Indoors March 13 Mar 13 – Mar 27
Transplant Outdoors April 17 Apr 17 – May 1
Direct Sow April 3 Apr 3 – Apr 24
Harvest August 7 Aug 7 – Oct 2
Fall Sowing August 6 Aug 6 – Aug 20

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
July
August Fall Sowing Harvest
September Harvest
October Harvest
November
December
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Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

110–150 days

🧪 Soil pH

Needs 5.5–7 · Your soil: ideal

🗺️ USDA Zone

Zone 5b

📆 Growing Season

181 days in Knox County

Growing Tips for Belgian Endive in Knox County

Direct sow Belgian Endive outdoors after April 17 in Knox County when soil has warmed and frost danger has passed.

Common pests for Belgian Endive in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Grow chicory roots in the garden during summer, then dig in fall. Trim tops and force roots in moist sand in a dark cellar at 50-60F. Chicons emerge in 3-4 weeks.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Belgian Endive in Knox County, IL?

Knox County is in Zone 5b with an average last frost of April 17. Plan your Belgian Endive planting based on this frost date — see the calendar above for exact timing.

What planting zone is Knox County, IL?

Knox County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 17 and first fall frost is October 15.

When should I plant Belgian Endive in Knox County, ?

In Knox County, , plant Belgian Endive after the last frost (around April 17) and before the first frost (around October 15). Best results when soil holds above 50°F.

What growing zone is Knox County, for Belgian Endive?

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

Can Belgian Endive grow in Knox County's climate?

Yes — Belgian Endive grows well in Knox County's temperate climate. Knox County averages a 181-day frost-free season, with last frost around April 17 and first frost around October 15.

🌱

Your Knox County Garden Planner — Free

A 22-page printable planner built for Knox 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 Knox County, IL. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.