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When to plant Leeks in Monroe County County,

Plant Leeks in Monroe County County, when soil hits 50°F — usually March 29. Continue planting through April 19 for the spring crop. A second sowing from August 11 to August 25 extends the harvest into fall.

When to Plant Leeks in Monroe County, IN

Leeks
Monroe County, Indiana Zone 6b June

Top priorities for Monroe County, Indiana gardeners in June

If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.

Avg. last frost April 12
Avg. first frost October 20
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 14.7 hrs
Get ahead of July
  • First harvests: leeks

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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.

Monroe County, Indiana is in USDA Zone 6b. The average last spring frost is April 12 and the first fall frost is October 20, giving you a growing season of approximately 191 days.

At an elevation of 670 feet, Monroe County receives approximately 36.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Leeks during the growing season.

Monroe County, IN (Zone 6b) Moderate season
191 days
Last Spring Frost April 12
191 growing days
First Fall Frost October 20
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Monroe County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-7.2

Drainage

Well Drained

Leeks Planting Risk Windows

Early Start (70% safe) ✓ Fits season (24 days to spare)
Start indoors: Mar 4 Transplant: Apr 8 🍅 Harvest: Jul 8 – Sep 23
Recommended (50%) ✓ Fits season (23 days to spare)
Start indoors: Mar 8 Transplant: Apr 12 🍅 Harvest: Jul 12 – Sep 27
Safe Start (90%) ✓ Fits season (15 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 Monroe County

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

Soil pH

Your soil pH (6.3–7.2) overlaps with Leeks's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.6%) — 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.

Leeks Water Budget

Plant needs
0.8″/week
Rainfall provides
0.8″/week
Watering frequency Only during dry spells
Season total 3 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 1.7" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.8" 0" ❄️ Dormant
Apr 3.5" 3.8" 0" ✅ Rainfall sufficient
May 3.5" 4.1" 0" ✅ Rainfall sufficient
Jun 3.5" 4.1" 0" ✅ Rainfall sufficient
Jul 3.5" 3.7" 0" ✅ Rainfall sufficient
Aug 3.5" 4.2" 0" ✅ Rainfall sufficient
Sep 3.5" 3.1" 0.4" 💧 Light watering
Oct 3.5" 2.9" 0.6" 💧 Light watering
Nov 2.7" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Monroe 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 ~1,830 GDD — county provides 2,912 GDD Excellent fit

Leeks Planting Timeline — Monroe County, IN

Leeks Planting Calendar

Activity When Date Range
Start Indoors March 8 Mar 8 – Mar 22
Transplant Outdoors April 12 Apr 12 – Apr 26
Direct Sow March 29 Mar 29 – Apr 19
Harvest July 12 Jul 12 – Sep 27
Fall Sowing August 11 Aug 11 – Aug 25

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors Direct Sow
April Transplant Outdoors Direct Sow
May
June
July Harvest
August Fall Sowing Harvest
September Harvest
October
November
December
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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 6b

📆 Growing Season

191 days in Monroe County

Growing Tips for Leeks in Monroe County

Direct sow Leeks outdoors after April 12 in Monroe 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 Monroe County, IN?

Monroe County is in Zone 6b with an average last frost of April 12. Plan your Leeks planting based on this frost date — see the calendar above for exact timing.

What planting zone is Monroe County, IN?

Monroe County, Indiana is in USDA Hardiness Zone 6b. The average last spring frost is April 12 and first fall frost is October 20.

When should I plant Leeks in Monroe County, ?

In Monroe County, , plant Leeks after the last frost (around April 12) and before the first frost (around October 20). Best results when soil holds above 50°F.

What growing zone is Monroe County, for Leeks?

Monroe County sits in USDA Zone 6b. Leeks grows reliably in zones 3a through 10b, so it's a good fit here.

Can Leeks grow in Monroe County's climate?

Yes — Leeks grows well in Monroe County's temperate climate. Monroe County averages a 191-day frost-free season, with last frost around April 12 and first frost around October 20.

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Your Monroe County Garden Planner — Free

A 22-page printable planner built for Monroe County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Monroe County, IN. Local conditions may vary. Last updated: June 2026.

Sources & credits

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