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When to plant Endive in Custer County County,

Aim to plant Endive in Custer County County on or after June 4; the window stays open through June 25. Custer County County's 79-day frost-free season gives you a tight window — choose short-season varieties. A second sowing from June 27 to July 11 extends the harvest into fall.

When to Plant Endive in Custer County, ID

Custer County, Idaho Zone 5b June

June to-do list for Custer County, Idaho

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

Avg. last frost June 18
Avg. first frost September 5
Soil temp (4") 51°F
Watering High
Pest pressure High
Daylight 15.3 hrs
  1. Get endive in the ground

    Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.

  2. Outdoor sowing time: endive

    Mark the row. Birds and stray feet both have opinions about unmarked beds.

  3. Plant your fall garden: endive

    Keep young seedlings shaded and moist in summer heat. A row of taller crops works as natural shade.

Coming up in July — start thinking about
  • Starting indoors: 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.

Custer County, Idaho is in USDA Zone 5b. The average last spring frost is June 18 and the first fall frost is September 5, giving you a growing season of approximately 79 days.

At an elevation of 5,189 feet, Custer County receives approximately 20.6 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Endive to ensure they mature before fall.

Custer County, ID (Zone 5b) Very short season
79 days
Last Spring Frost June 18
79 growing days
First Fall Frost September 5

Custer County Soil Profile

Soil Type

Loam

Soil pH

6.3-8

Drainage

Well Drained

Endive Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: May 7 Transplant: Jun 11 🍅 Harvest: Jul 30 – Sep 3
Recommended (50%) ✗ May not fit
Start indoors: May 14 Transplant: Jun 18 🍅 Harvest: Aug 6 – Sep 10
Safe Start (90%) ✓ Fits season (7 days to spare)
Start indoors: May 25 Transplant: Jun 29 🍅 Harvest: Aug 17 – Sep 21

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 Custer County

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

Soil pH

Your soil pH (6.3–8.0) is more alkaline than Endive prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Endive.

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.

Endive Water Budget

Plant needs
0.7″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 1.3" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 2.4" 0" ❄️ Dormant
May 2.3" 0" ❄️ Dormant
Jun 3" 1.5" 1.5" 🚿 Regular watering
Jul 3" 2" 1" 💧 Light watering
Aug 3" 2.1" 0.9" 💧 Light watering
Sep 3" 1.7" 1.3" 💧 Light watering
Oct 1.6" 0" ❄️ Dormant
Nov 1.4" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Custer 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 ~550 GDD — county provides 790 GDD Excellent fit

Endive Planting Timeline — Custer County, ID

Endive Planting Calendar

Activity When Date Range
Start Indoors May 14 May 14 – May 28
Transplant Outdoors June 18 Jun 18 – Jul 2
Direct Sow June 4 Jun 4 – Jun 25
Harvest August 6 Aug 6 – Sep 10
Fall Sowing June 27 Jun 27 – Jul 11

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.7"/week · Natural rainfall sufficient

📅 Days to Maturity

45–65 days

🧪 Soil pH

Needs 5.5–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5b

📆 Growing Season

79 days in Custer County

Growing Tips for Endive in Custer County

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

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 →

Frequently Asked Questions

When should I plant Endive in Custer County, ID?

Custer County is in Zone 5b with an average last frost of June 18. Plan your Endive planting based on this frost date — see the calendar above for exact timing.

What planting zone is Custer County, ID?

Custer County, Idaho is in USDA Hardiness Zone 5b. The average last spring frost is June 18 and first fall frost is September 5.

When should I plant Endive in Custer County, ?

In Custer County, , plant Endive after the last frost (around June 18) and before the first frost (around September 5). Best results when soil holds above 50°F.

What growing zone is Custer County, for Endive?

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

Can Endive grow in Custer County's climate?

Yes — Endive grows well in Custer County's temperate climate. Custer County averages a 79-day frost-free season, with last frost around June 18 and first frost around September 5.

🌱

Your Custer County Garden Planner — Free

A 22-page printable planner built for Custer 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 Custer County, ID. 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.