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When to Plant Leeks in Forsyth County, NC

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.

Forsyth County, North Carolina is in USDA Zone 7b. The average last spring frost is April 11 and the first fall frost is October 22, giving you a growing season of approximately 194 days.

At an elevation of 424 feet, Forsyth County receives approximately 44.4 inches of rainfall annually with predominantly clay loam soil. Summer highs average 90ยฐF, providing good warmth for Leeks during the growing season. Clay soil retains moisture well for Leeks, but amend with compost to improve drainage and prevent root rot.

Forsyth County, NC (Zone 7b) Moderate season
194 days
Last Spring Frost April 11
194 growing days
First Fall Frost October 22

Forsyth County Soil Profile

Soil Type

Clay Loam

Soil pH

5.7-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (26 days to spare)
Start indoors: Mar 3 Transplant: Apr 7 🍅 Harvest: Jul 7 – Sep 22
Recommended (50%) ✓ Fits season (26 days to spare)
Start indoors: Mar 7 Transplant: Apr 11 🍅 Harvest: Jul 11 – Sep 26
Safe Start (90%) ✓ Fits season (21 days to spare)
Start indoors: Mar 27 Transplant: May 1 🍅 Harvest: Jul 31 – Oct 16

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 Forsyth County

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

Soil pH

Your soil pH (5.7โ€“6.3) overlaps with Leeks's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.4%). 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
1.0″/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€” 4.1" 0" โ„๏ธ Dormant
Feb โ€” 3.5" 0" โ„๏ธ Dormant
Mar โ€” 4.2" 0" โ„๏ธ Dormant
Apr 3.5" 3.1" 0.4" ๐Ÿ’ง Light watering
May 3.5" 3.8" 0" โœ… Rainfall sufficient
Jun 3.5" 4.2" 0" โœ… Rainfall sufficient
Jul 3.5" 4.5" 0" โœ… Rainfall sufficient
Aug 3.5" 4.1" 0" โœ… Rainfall sufficient
Sep 3.5" 3.1" 0.4" ๐Ÿ’ง Light watering
Oct 3.5" 3" 0.5" ๐Ÿ’ง Light watering
Nov โ€” 3.7" 0" โ„๏ธ Dormant
Dec โ€” 3" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Forsyth 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 ~2,100 GDD — county provides 3,395 GDD Excellent fit

Leeks Planting Timeline โ€” Forsyth County, NC

Leeks Planting Calendar

Activity When Date Range
Start Indoors March 7 Mar 7 โ€“ Mar 21
Transplant Outdoors April 11 Apr 11 โ€“ Apr 25
Direct Sow March 28 Mar 28 โ€“ Apr 18
Harvest July 11 Jul 11 โ€“ Sep 26
Fall Sowing August 13 Aug 13 โ€“ Aug 27

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

Month-by-Month Timeline

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

๐Ÿ—บ๏ธ USDA Zone

Zone 7b

๐Ÿ“† Growing Season

194 days in Forsyth County

Growing Tips for Leeks in Forsyth County

Direct sow Leeks outdoors after April 11 in Forsyth County when soil has warmed and frost danger has passed.

With Forsyth County's clay soil (29% clay), work in 3-4 inches of compost before planting Leeks. Avoid tilling when soil is wet to prevent compaction.

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 Forsyth County, NC?

Forsyth County is in Zone 7b with an average last frost of April 11. Plan your Leeks planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Forsyth County, NC?

Forsyth County, North Carolina is in USDA Hardiness Zone 7b. The average last spring frost is April 11 and first fall frost is October 22.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Forsyth 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 Forsyth County, NC. Local conditions may vary. Last updated: April 2026.