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When to Plant Belgian Endive in Boise County, ID

Boise County, Idaho Zone 7a May

May in Boise County, Idaho — your action list

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

Avg. last frost May 18
Avg. first frost September 27
Soil temp (4") 34°F
Watering Moderate
Pest pressure Low
Daylight 14.6 hrs
  1. Harden off and plant belgian endive

    Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.

  2. Put belgian endive seeds straight in the ground

    Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.

June prep starts now
  • 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.

Boise County, Idaho is in USDA Zone 7a. The average last spring frost is May 18 and the first fall frost is September 27, giving you a growing season of approximately 132 days.

At an elevation of 8,023 feet, Boise County receives approximately 24.3 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Belgian Endive during the growing season.

Boise County, ID (Zone 7a) Short season
132 days
Last Spring Frost May 18
132 growing days
First Fall Frost September 27

Boise County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 31 Transplant: May 5 🍅 Harvest: Aug 25 – Oct 20
Recommended (50%) ✗ May not fit
Start indoors: Apr 13 Transplant: May 18 🍅 Harvest: Sep 7 – Nov 2
Safe Start (90%) ✗ May not fit
Start indoors: May 12 Transplant: Jun 16 🍅 Harvest: Oct 6 – Dec 1

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 Boise County

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

Soil pH

Your soil pH (6.7–7.7) 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 Boise County is excellent for Belgian Endive — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.3%). 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
0.8″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 320 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 1.8" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 2.4" 0" ❄️ Dormant
May 4.3" 3" 1.3" 💧 Light watering
Jun 4.3" 1.9" 2.4" 🚿 Regular watering
Jul 4.3" 1.8" 2.5" 🚿 Regular watering
Aug 4.3" 2.8" 1.5" 💧 Light watering
Sep 4.3" 1.7" 2.6" 🚿 Regular watering
Oct 2.4" 0" ❄️ Dormant
Nov 1.5" 0" ❄️ Dormant
Dec 1.5" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Boise 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 1,914 GDD Good fit

Belgian Endive Planting Timeline — Boise County, ID

Belgian Endive Planting Calendar

Activity When Date Range
Start Indoors April 13 Apr 13 – Apr 27
Transplant Outdoors May 18 May 18 – Jun 1
Direct Sow May 4 May 4 – May 25
Harvest September 7 Sep 7 – Nov 2
Fall Sowing July 19 Jul 19 – Aug 2

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

Month-by-Month Timeline

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

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: too_alkaline

🗺️ USDA Zone

Zone 7a

📆 Growing Season

132 days in Boise County

Growing Tips for Belgian Endive in Boise County

Direct sow Belgian Endive outdoors after May 18 in Boise County when soil has warmed and frost danger has passed.

Your 132.0-day growing season in Boise 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.

Boise County receives only 24" 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 Boise County, ID?

Boise County is in Zone 7a with an average last frost of May 18. Plan your Belgian Endive planting based on this frost date — see the calendar above for exact timing.

What planting zone is Boise County, ID?

Boise County, Idaho is in USDA Hardiness Zone 7a. The average last spring frost is May 18 and first fall frost is September 27.

🌱

Your Boise County Garden Planner — Free

A 24-page printable planner built for Boise County (Zone 7a). 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 Boise 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.