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When to Plant Leeks in Sarpy County, NE

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.

Sarpy County, Nebraska is in USDA Zone 5a. The average last spring frost is April 23 and the first fall frost is October 11, giving you a growing season of approximately 171 days.

At an elevation of 502 feet, Sarpy County receives approximately 27.1 inches of rainfall annually with predominantly loam soil. Summer highs average 86ยฐF, providing good warmth for Leeks during the growing season.

Sarpy County, NE (Zone 5a) Moderate season
171 days
Last Spring Frost April 23
171 growing days
First Fall Frost October 11

Sarpy County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (3 days to spare)
Start indoors: Mar 14 Transplant: Apr 18 🍅 Harvest: Jul 18 – Oct 3
Recommended (50%) ✓ Fits season (3 days to spare)
Start indoors: Mar 19 Transplant: Apr 23 🍅 Harvest: Jul 23 – Oct 8
Safe Start (90%) ✗ May not fit
Start indoors: Apr 5 Transplant: May 10 🍅 Harvest: Aug 9 – Oct 25

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 Sarpy County

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

Soil pH

Your soil pH (6.7โ€“7.9) is more alkaline than Leeks prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.7%). 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
0.2″/week
Watering frequency Only during dry spells
Season total 245 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" 0" โ„๏ธ Dormant
Mar โ€” 1.8" 0" โ„๏ธ Dormant
Apr 3.5" 2.9" 0.6" ๐Ÿ’ง Light watering
May 3.5" 3.8" 0" โœ… Rainfall sufficient
Jun 3.5" 3.9" 0" โœ… Rainfall sufficient
Jul 3.5" 3.2" 0.3" ๐Ÿ’ง Light watering
Aug 3.5" 3.4" 0.1" ๐Ÿ’ง Light watering
Sep 3.5" 2.9" 0.6" ๐Ÿ’ง Light watering
Oct 3.5" 1.7" 1.8" ๐Ÿšฟ Regular watering
Nov โ€” 1" 0" โ„๏ธ Dormant
Dec โ€” 0.7" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Sarpy 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 ~1,740 GDD — county provides 2,479 GDD Excellent fit

Leeks Planting Timeline โ€” Sarpy County, NE

Leeks Planting Calendar

Activity When Date Range
Start Indoors March 19 Mar 19 โ€“ Apr 2
Transplant Outdoors April 23 Apr 23 โ€“ May 7
Direct Sow April 9 Apr 9 โ€“ Apr 30
Harvest July 23 Jul 23 โ€“ Oct 8
Fall Sowing August 2 Aug 2 โ€“ Aug 16

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.8"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

90โ€“150 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 5a

๐Ÿ“† Growing Season

171 days in Sarpy County

Growing Tips for Leeks in Sarpy County

Direct sow Leeks outdoors after April 23 in Sarpy 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 Sarpy County, NE?

Sarpy County is in Zone 5a with an average last frost of April 23. Plan your Leeks planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Sarpy County, NE?

Sarpy County, Nebraska is in USDA Hardiness Zone 5a. The average last spring frost is April 23 and first fall frost is October 11.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Sarpy County gardeners in Zone 5a 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 Sarpy County, NE. Local conditions may vary. Last updated: April 2026.