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When to Plant Belgian Endive in Bonner County, ID

Bonner County, Idaho Zone 6b May

May in Bonner County, Idaho — your action list

We've pulled the most time-sensitive tasks for Bonner County, Idaho this May and put them front and centre. Tackle them in order.

Avg. last frost May 5
Avg. first frost October 3
Soil temp (4") 34°F
Watering High
Pest pressure Low
Daylight 15 hrs
  1. Time to transplant belgian endive

    Frost risk is low now in Bonner County, Idaho. If you've been covering beds overnight, you can stop.

Get ahead of June
  • Starting indoors: belgian endive

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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.

Bonner County, Idaho is in USDA Zone 6b. The average last spring frost is May 5 and the first fall frost is October 3, giving you a growing season of approximately 151 days.

At an elevation of 7,480 feet, Bonner County receives approximately 12.9 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Belgian Endive during the growing season. With low rainfall, drip irrigation is essential for growing Belgian Endive successfully. Mulch heavily to conserve soil moisture.

Bonner County, ID (Zone 6b) Moderate season
151 days
Last Spring Frost May 5
151 growing days
First Fall Frost October 3

Bonner County Soil Profile

Soil Type

Loam

Soil pH

6.4-8.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 24 Transplant: Apr 28 🍅 Harvest: Aug 18 – Oct 13
Recommended (50%) ✗ May not fit
Start indoors: Mar 31 Transplant: May 5 🍅 Harvest: Aug 25 – Oct 20
Safe Start (90%) ✗ May not fit
Start indoors: Apr 27 Transplant: Jun 1 🍅 Harvest: Sep 21 – Nov 16

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 Bonner County

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

Soil pH

Your soil pH (6.4–8.2) is more alkaline than Belgian Endive prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help Belgian Endive.

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.4″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,034 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 0.9" 0" ❄️ Dormant
Feb 0.7" 0" ❄️ Dormant
Mar 1.1" 0" ❄️ Dormant
Apr 1.5" 0" ❄️ Dormant
May 4.3" 1.5" 2.8" 🚿 Regular watering
Jun 4.3" 0.9" 3.4" 🚿 Regular watering
Jul 4.3" 1.1" 3.2" 🚿 Regular watering
Aug 4.3" 1.2" 3.1" 🚿 Regular watering
Sep 4.3" 1.1" 3.2" 🚿 Regular watering
Oct 4.3" 1.1" 3.2" 🚿 Regular watering
Nov 0.9" 0" ❄️ Dormant
Dec 0.7" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Bonner 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 ~1,885 GDD — county provides 2,189 GDD Good fit

Belgian Endive Planting Timeline — Bonner County, ID

Belgian Endive Planting Calendar

Activity When Date Range
Start Indoors March 31 Mar 31 – Apr 14
Transplant Outdoors May 5 May 5 – May 19
Direct Sow April 21 Apr 21 – May 12
Harvest August 25 Aug 25 – Oct 20
Fall Sowing July 25 Jul 25 – Aug 8

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors Direct Sow
May Transplant Outdoors Direct Sow
June
July Fall Sowing
August Fall Sowing Harvest
September Harvest
October Harvest
November
December

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

110–150 days

🧪 Soil pH

Needs 5.5–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6b

📆 Growing Season

151 days in Bonner County

Growing Tips for Belgian Endive in Bonner County

Direct sow Belgian Endive outdoors after May 05 in Bonner County when soil has warmed and frost danger has passed.

Your 151.0-day growing season in Bonner County is tight for Belgian Endive (110.0-150.0 days to maturity). Start indoors and choose early-maturing varieties.

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

Bonner County receives only 13" of rain annually. Belgian Endive needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Bonner County, ID?

Bonner County is in Zone 6b with an average last frost of May 5. Plan your Belgian Endive planting based on this frost date — see the calendar above for exact timing.

What planting zone is Bonner County, ID?

Bonner County, Idaho is in USDA Hardiness Zone 6b. The average last spring frost is May 5 and first fall frost is October 3.

🌱

Your Bonner County Garden Planner — Free

A 24-page printable planner built for Bonner County (Zone 6b). 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 Bonner County, ID. Local conditions may vary. Last updated: May 2026.

Sources & credits

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