Blog

When to Plant Leeks in Trumbull County, OH

Trumbull County, Ohio Zone 6a May

Your May planting checklist for Trumbull County, Ohio

May is a pivotal month for Trumbull County, Ohio gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 4
Avg. first frost October 17
Soil temp (4") 60°F
Watering Low
Pest pressure Low
Daylight 14.3 hrs
  1. Harden off and plant leeks

    Harden off for 7 days — a little more sun each day — before planting. That's the difference between a seedling that thrives and one that stalls.

June prep starts now
  • 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.

Trumbull County, Ohio is in USDA Zone 6a. The average last spring frost is May 4 and the first fall frost is October 17, giving you a growing season of approximately 166 days.

At an elevation of 651 feet, Trumbull County receives approximately 34.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Leeks during the growing season.

Trumbull County, OH (Zone 6a) Moderate season
166 days
Last Spring Frost May 4
166 growing days
First Fall Frost October 17

Trumbull County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 24 Transplant: Apr 28 🍅 Harvest: Jul 28 – Oct 13
Recommended (50%) ✗ May not fit
Start indoors: Mar 30 Transplant: May 4 🍅 Harvest: Aug 3 – Oct 19
Safe Start (90%) ✗ May not fit
Start indoors: Apr 17 Transplant: May 22 🍅 Harvest: Aug 21 – Nov 6

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 Trumbull County

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

Soil pH

Your soil pH (5.7–7.3) overlaps with Leeks's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Trumbull 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 10 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 1.3" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 3.2" 0" ❄️ Dormant
May 3.5" 4.4" 0" ✅ Rainfall sufficient
Jun 3.5" 4.7" 0" ✅ Rainfall sufficient
Jul 3.5" 4" 0" ✅ Rainfall sufficient
Aug 3.5" 3.2" 0.3" 💧 Light watering
Sep 3.5" 3.6" 0" ✅ Rainfall sufficient
Oct 3.5" 2.5" 1" 💧 Light watering
Nov 2.5" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Trumbull 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 ~1,740 GDD — county provides 2,407 GDD Excellent fit

Leeks Planting Timeline — Trumbull County, OH

Leeks Planting Calendar

Activity When Date Range
Start Indoors March 30 Mar 30 – Apr 13
Transplant Outdoors May 4 May 4 – May 18
Direct Sow April 20 Apr 20 – May 11
Harvest August 3 Aug 3 – Oct 19
Fall Sowing August 8 Aug 8 – Aug 22

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.8"/week · Natural rainfall sufficient

📅 Days to Maturity

90–150 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

166 days in Trumbull County

Growing Tips for Leeks in Trumbull County

Direct sow Leeks outdoors after May 04 in Trumbull 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 Trumbull County, OH?

Trumbull County is in Zone 6a with an average last frost of May 4. Plan your Leeks planting based on this frost date — see the calendar above for exact timing.

What planting zone is Trumbull County, OH?

Trumbull County, Ohio is in USDA Hardiness Zone 6a. The average last spring frost is May 4 and first fall frost is October 17.

🌱

Your Trumbull County Garden Planner — Free

A 24-page printable planner built for Trumbull County (Zone 6a). 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 Trumbull County, OH. 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.