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When to Plant Leeks in Broadbent, OR

Leeks
Coos County, Oregon Zone 9a June

June to-do list for Coos County, Oregon

June is a pivotal month for Coos County, Oregon gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost March 22
Avg. first frost November 19
Soil temp (4") 81°F
Watering High
Pest pressure High
Daylight 15.2 hrs
  1. It's harvest week for leeks

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

A few tasks this June that'll pay off in July
  • First harvests: leeks

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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.

Broadbent, Oregon is in USDA Zone 9a. The average last spring frost is March 22 and the first fall frost is November 19, giving you a growing season of approximately 242 days.

At an elevation of 96 feet, Coos County receives approximately 38.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Leeks during the growing season.

Broadbent, OR (Zone 9a) Long season
242 days
Last Spring Frost March 22
242 growing days
First Fall Frost November 19

Broadbent Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.8

Drainage

Well Drained

Leeks Planting Risk Windows

Early Start (70% safe) ✓ Fits season (71 days to spare)
Start indoors: Feb 7 Transplant: Mar 7 🍅 Harvest: Jun 6 – Aug 22
Recommended (50%) ✓ Fits season (74 days to spare)
Start indoors: Feb 22 Transplant: Mar 22 🍅 Harvest: Jun 21 – Sep 6
Safe Start (90%) ✓ Fits season (69 days to spare)
Start indoors: Mar 25 Transplant: Apr 22 🍅 Harvest: Jul 22 – Oct 7

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 Broadbent

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

Soil pH

Your soil pH (5.4–6.8) overlaps with Leeks's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.7%) — Leeks will thrive.

How to Plant Leeks

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Leeks Water Budget

Plant needs
0.8″/week
Rainfall provides
0.7″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 273 gal / 100 sq ft

Monthly Watering Guide for Leeks

Leeks needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.

Month Leeks Needs Rainfall You Supplement Action
Jan 5.5" 0" ❄️ Dormant
Feb 4.5" 0" ❄️ Dormant
Mar 3.5" 4.4" 0" ✅ Rainfall sufficient
Apr 3.5" 3.1" 0.4" 💧 Light watering
May 3.5" 2.3" 1.2" 💧 Light watering
Jun 3.5" 1.6" 1.9" 🚿 Regular watering
Jul 3.5" 0.6" 2.9" 🚿 Regular watering
Aug 3.5" 0.8" 2.7" 🚿 Regular watering
Sep 3.5" 1.4" 2.1" 🚿 Regular watering
Oct 3.5" 3.3" 0.2" 💧 Light watering
Nov 3.5" 5.9" 0" ✅ Rainfall sufficient
Dec 5.5" 0" ❄️ Dormant

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

Leeks 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.

Leeks needs ~2,010 GDD — county provides 4,053 GDD Excellent fit

Leeks Planting Timeline — Broadbent, OR

Leeks Planting Calendar

Activity When Date Range
Start Indoors February 22 Feb 22 – Mar 8
Transplant Outdoors March 22 Mar 22 – Apr 5
Direct Sow March 1 Mar 1 – Mar 22
Harvest June 21 Jun 21 – Sep 6
Fall Sowing September 24 Sep 24 – Oct 8

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.8"/week · Only during dry spells

📅 Days to Maturity

90–150 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 9a

📆 Growing Season

242 days in Coos County

Growing Tips for Leeks in Broadbent

Direct sow Leeks outdoors after March 22 in Coos County when soil has warmed and frost danger has passed.

Common pests for Leeks in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.

General growing tips

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 →

🌱

Your Coos County Garden Planner — Free

A 22-page printable planner built for Coos County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Coos County, OR. Local conditions may vary. Last updated: June 2026.