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When to Plant Leeks in Miami County, KS

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.

Miami County, Kansas is in USDA Zone 6a. The average last spring frost is April 12 and the first fall frost is October 25, giving you a growing season of approximately 196 days.

At an elevation of 689 feet, Miami County receives approximately 21.7 inches of rainfall annually with predominantly loam soil. Summer highs average 88ยฐF, providing good warmth for Leeks during the growing season.

Miami County, KS (Zone 6a) Moderate season
196 days
Last Spring Frost April 12
196 growing days
First Fall Frost October 25

Miami County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (26 days to spare)
Start indoors: Mar 2 Transplant: Apr 6 🍅 Harvest: Jul 6 – Sep 21
Recommended (50%) ✓ Fits season (28 days to spare)
Start indoors: Mar 8 Transplant: Apr 12 🍅 Harvest: Jul 12 – Sep 27
Safe Start (90%) ✓ Fits season (24 days to spare)
Start indoors: Mar 23 Transplant: Apr 27 🍅 Harvest: Jul 27 – Oct 12

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 Miami County

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

Soil pH

Your soil pH (6.5โ€“7.7) is more alkaline than Leeks prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.1%) 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
0.5″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 584 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€” 0.5" 0" โ„๏ธ Dormant
Feb โ€” 0.8" 0" โ„๏ธ Dormant
Mar โ€” 1.2" 0" โ„๏ธ Dormant
Apr 3.5" 2.1" 1.4" ๐Ÿ’ง Light watering
May 3.5" 3.2" 0.3" ๐Ÿ’ง Light watering
Jun 3.5" 3.2" 0.3" ๐Ÿ’ง Light watering
Jul 3.5" 3" 0.5" ๐Ÿ’ง Light watering
Aug 3.5" 2.8" 0.7" ๐Ÿ’ง Light watering
Sep 3.5" 2.2" 1.3" ๐Ÿ’ง Light watering
Oct 3.5" 1.5" 2" ๐Ÿšฟ Regular watering
Nov โ€” 0.6" 0" โ„๏ธ Dormant
Dec โ€” 0.6" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Miami 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 ~1,920 GDD — county provides 3,136 GDD Excellent fit

Leeks Planting Timeline โ€” Miami County, KS

Leeks Planting Calendar

Activity When Date Range
Start Indoors March 8 Mar 8 โ€“ Mar 22
Transplant Outdoors April 12 Apr 12 โ€“ Apr 26
Direct Sow March 29 Mar 29 โ€“ Apr 19
Harvest July 12 Jul 12 โ€“ Sep 27
Fall Sowing August 16 Aug 16 โ€“ Aug 30

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 1-2 times/week

๐Ÿ“… Days to Maturity

90โ€“150 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

196 days in Miami County

Growing Tips for Leeks in Miami County

Direct sow Leeks outdoors after April 12 in Miami 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 Miami County, KS?

Miami County is in Zone 6a with an average last frost of April 12. Plan your Leeks planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Miami County, KS?

Miami County, Kansas is in USDA Hardiness Zone 6a. The average last spring frost is April 12 and first fall frost is October 25.

๐ŸŒฑ

Plan Your Garden with Confidence

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