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When to plant Leeks in Custer County County,

Custer County County sits in USDA Zone 5b. Plant Leeks between June 4 (after last frost on June 18) and June 25. A second sowing from June 27 to July 11 extends the harvest into fall.

When to Plant Leeks in Custer County, ID

Leeks

Leeks are a mild, sweet allium that produces long white shanks. They are more refined than onions and are a key ingredient in soups, stews, and gratins.

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 Leeks 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
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Custer County Soil Profile

Soil Type

Loam

Soil pH

6.3-8

Drainage

Well Drained

Monthly Watering Guide for Leeks

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

Month Leeks 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 4.3" 1.5" 2.8" 🚿 Regular watering
Jul 4.3" 2" 2.3" 🚿 Regular watering
Aug 4.3" 2.1" 2.2" 🚿 Regular watering
Sep 4.3" 1.7" 2.6" 🚿 Regular 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.

Leeks Planting Timeline — Custer County, ID

Leeks 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 September 17 Sep 17 – Dec 3
Fall Sowing June 27 Jun 27 – Jul 11

Plant 1" deep · 15" apart · Rows 24" 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
September Harvest
October Harvest
November Harvest
December Harvest
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

90–150 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 5b

📆 Growing Season

79 days in Custer County

Growing Tips for Custer County

Start seeds indoors 10-12 weeks before last frost. Transplant into trenches and hill soil around stems as they grow to increase the white portion. Harvest as needed.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Leeks in Custer County, ID?

Custer County is in Zone 5b with an average last frost of June 18. Plan your Leeks 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 Leeks in Custer County County, ?

In Custer County County, , plant Leeks 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 County, for Leeks?

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

Can Leeks grow in Custer County County's climate?

Yes — Leeks grows well in Custer County County's temperate climate. Custer County 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

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