Blog

When to Plant Leeks in Burleigh County, ND

Burleigh County, North Dakota Zone 4a May

Top priorities for Burleigh County, North Dakota gardeners in May

We've pulled the most time-sensitive tasks for Burleigh County, North Dakota this May and put them front and centre. Tackle them in order.

Avg. last frost May 12
Avg. first frost September 27
Soil temp (4") 56°F
Watering Moderate
Pest pressure Low
Daylight 14.8 hrs
  1. Transplant leeks outside

    Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.

  2. Sow leeks where they'll grow

    These tolerate cool soil, so you're not gambling by sowing now.

Coming up in June — start thinking about
  • Starting indoors: leeks

Instant PDF download. No spam, unsubscribe any time.

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.

Burleigh County, North Dakota is in USDA Zone 4a. The average last spring frost is May 12 and the first fall frost is September 27, giving you a growing season of approximately 138 days.

At an elevation of 1,102 feet, Burleigh County receives approximately 23.1 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Leeks to ensure they mature before fall.

Burleigh County, ND (Zone 4a) Short season
138 days
Last Spring Frost May 12
138 growing days
First Fall Frost September 27
Share this guide:

Burleigh County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 26 Transplant: May 7 🍅 Harvest: Aug 6 – Oct 1
Recommended (50%) ✗ May not fit
Start indoors: Mar 31 Transplant: May 12 🍅 Harvest: Aug 11 – Oct 6
Safe Start (90%) ✗ May not fit
Start indoors: Apr 14 Transplant: May 26 🍅 Harvest: Aug 25 – Oct 20

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 Burleigh County

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

Soil pH

Your soil pH (6.7–7.3) overlaps with Leeks's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.8%). Annual compost additions will help Leeks.

How to Plant Leeks

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

Fall planting: Sow 12 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
0.1″/week
Watering frequency Only during dry spells
Season total 143 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 1.7" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 2.2" 0" ❄️ Dormant
May 3.5" 3" 0.5" 💧 Light watering
Jun 3.5" 1.5" 2" 🚿 Regular watering
Jul 3.5" 1.8" 1.7" 💧 Light watering
Aug 3.5" 2.7" 0.8" 💧 Light watering
Sep 3.5" 1.9" 1.6" 💧 Light watering
Oct 2.2" 0" ❄️ Dormant
Nov 1.6" 0" ❄️ Dormant
Dec 1.3" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Burleigh 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 ~1,380 GDD — county provides 1,587 GDD Good fit

Leeks Planting Timeline — Burleigh County, ND

Leeks Planting Calendar

Activity When Date Range
Start Indoors March 31 Mar 31 – Apr 14
Transplant Outdoors May 12 May 12 – May 26
Direct Sow May 5 May 5 – May 26
Harvest August 11 Aug 11 – Oct 6
Fall Sowing July 5 Jul 5 – Jul 19

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

Month-by-Month Timeline

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

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 4a

📆 Growing Season

138 days in Burleigh County

Growing Tips for Leeks in Burleigh County

Direct sow Leeks outdoors after May 12 in Burleigh County when soil has warmed and frost danger has passed.

Your 138.0-day growing season in Burleigh 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 Burleigh County, ND?

Burleigh County is in Zone 4a with an average last frost of May 12. Plan your Leeks planting based on this frost date — see the calendar above for exact timing.

What planting zone is Burleigh County, ND?

Burleigh County, North Dakota is in USDA Hardiness Zone 4a. The average last spring frost is May 12 and first fall frost is September 27.

🌱

Your Burleigh County Garden Planner — Free

A 24-page printable planner built for Burleigh County (Zone 4a). 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 Burleigh County, ND. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.