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When to Plant Leeks in Klamath County, OR

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.

Klamath County, Oregon is in USDA Zone 6a. The average last spring frost is June 13 and the first fall frost is September 21, giving you a growing season of approximately 100 days.

At an elevation of 142 feet, Klamath County receives approximately 48.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Leeks to ensure they mature before fall.

Klamath County, OR (Zone 6a) Short season
100 days
Last Spring Frost June 13
100 growing days
First Fall Frost September 21

Klamath County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 25 Transplant: May 30 🍅 Harvest: Aug 29 – Nov 14
Recommended (50%) ✗ May not fit
Start indoors: May 9 Transplant: Jun 13 🍅 Harvest: Sep 12 – Nov 28
Safe Start (90%) ✗ May not fit
Start indoors: May 22 Transplant: Jun 26 🍅 Harvest: Sep 25 – Dec 11

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 Klamath County

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

Soil pH

Your soil pH (5.5โ€“6.3) is more acidic than Leeks prefers (6.0โ€“7.0). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Klamath County is excellent for Leeks โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Leeks.

Organic Matter

Organic matter is excellent (5.1%) โ€” Leeks will thrive.

How to Plant Leeks

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
2.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 โ€” 7.4" 0" โ„๏ธ Dormant
Feb โ€” 5.2" 0" โ„๏ธ Dormant
Mar โ€” 4.8" 0" โ„๏ธ Dormant
Apr โ€” 3.3" 0" โ„๏ธ Dormant
May โ€” 3" 0" โ„๏ธ Dormant
Jun 3.5" 1.8" 1.7" ๐Ÿ’ง Light watering
Jul 3.5" 0.9" 2.6" ๐Ÿšฟ Regular watering
Aug 3.5" 0.8" 2.7" ๐Ÿšฟ Regular watering
Sep 3.5" 2.1" 1.4" ๐Ÿ’ง Light watering
Oct โ€” 4.8" 0" โ„๏ธ Dormant
Nov โ€” 7.7" 0" โ„๏ธ Dormant
Dec โ€” 6.9" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Junโ€“Sep in Klamath County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~1,470 GDD — county provides 1,225 GDD May not mature

Leeks Planting Timeline โ€” Klamath County, OR

Leeks Planting Calendar

Activity When Date Range
Start Indoors May 9 May 9 โ€“ May 23
Transplant Outdoors June 13 Jun 13 โ€“ Jun 27
Direct Sow May 30 May 30 โ€“ Jun 20
Harvest September 12 Sep 12 โ€“ Nov 28
Fall Sowing July 13 Jul 13 โ€“ Jul 27

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.8"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

90โ€“150 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

100 days in Klamath County

Growing Tips for Leeks in Klamath County

Direct sow Leeks outdoors after June 13 in Klamath County when soil has warmed and frost danger has passed.

Your 100.0-day growing season in Klamath County is tight for Leeks (90.0-150.0 days to maturity). Start indoors and choose early-maturing varieties.

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 →

Frequently Asked Questions

When should I plant Leeks in Klamath County, OR?

Klamath County is in Zone 6a with an average last frost of June 13. Plan your Leeks planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Klamath County, OR?

Klamath County, Oregon is in USDA Hardiness Zone 6a. The average last spring frost is June 13 and first fall frost is September 21.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Klamath County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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