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When to Plant Leeks in Carter County, OK

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.

Carter County, Oklahoma is in USDA Zone 7b. The average last spring frost is March 28 and the first fall frost is November 2, giving you a growing season of approximately 219 days.

At an elevation of 648 feet, Carter County receives approximately 34.2 inches of rainfall annually with predominantly loam soil. Summer highs average 93ยฐF, providing good warmth for Leeks during the growing season.

Carter County, OK (Zone 7b) Long season
219 days
Last Spring Frost March 28
219 growing days
First Fall Frost November 2

Carter County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (53 days to spare)
Start indoors: Feb 14 Transplant: Mar 21 🍅 Harvest: Jun 20 – Sep 5
Recommended (50%) ✓ Fits season (51 days to spare)
Start indoors: Feb 21 Transplant: Mar 28 🍅 Harvest: Jun 27 – Sep 12
Safe Start (90%) ✓ Fits season (52 days to spare)
Start indoors: Mar 13 Transplant: Apr 17 🍅 Harvest: Jul 17 – Oct 2

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 Carter County

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

Soil pH

Your soil pH (6.4โ€“7.5) overlaps with Leeks's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

The loam soil in Carter 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 moderate (3.3%). Annual compost additions will help Leeks.

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
0.7″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 898 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

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€” 0.8" 0" โ„๏ธ Dormant
Feb โ€” 1.3" 0" โ„๏ธ Dormant
Mar 3.5" 1.9" 1.6" ๐Ÿ’ง Light watering
Apr 3.5" 3.1" 0.4" ๐Ÿ’ง Light watering
May 3.5" 5.8" 0" โœ… Rainfall sufficient
Jun 3.5" 6" 0" โœ… Rainfall sufficient
Jul 3.5" 4.3" 0" โœ… Rainfall sufficient
Aug 3.5" 3.9" 0" โœ… Rainfall sufficient
Sep 3.5" 2.8" 0.7" ๐Ÿ’ง Light watering
Oct 3.5" 2.3" 1.2" ๐Ÿ’ง Light watering
Nov 3.5" 1.2" 2.3" ๐Ÿšฟ Regular watering
Dec โ€” 0.9" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Carter 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 ~2,370 GDD — county provides 4,325 GDD Excellent fit

Leeks Planting Timeline โ€” Carter County, OK

Leeks Planting Calendar

Activity When Date Range
Start Indoors February 21 Feb 21 โ€“ Mar 7
Transplant Outdoors March 28 Mar 28 โ€“ Apr 11
Direct Sow March 14 Mar 14 โ€“ Apr 4
Harvest June 27 Jun 27 โ€“ Sep 12
Fall Sowing August 24 Aug 24 โ€“ Sep 7

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.8"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

90โ€“150 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 7b

๐Ÿ“† Growing Season

219 days in Carter County

Growing Tips for Leeks in Carter County

Direct sow Leeks outdoors after March 28 in Carter 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 →

Frequently Asked Questions

When should I plant Leeks in Carter County, OK?

Carter County is in Zone 7b with an average last frost of March 28. Plan your Leeks planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Carter County, OK?

Carter County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is March 28 and first fall frost is November 2.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Carter County gardeners in Zone 7b 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 Carter County, OK. Local conditions may vary. Last updated: April 2026.