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When to Plant Corn in Somerset County, ME

Somerset County, Maine Zone 5a May

May in Somerset County, Maine — your action list

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

Avg. last frost May 22
Avg. first frost September 26
Soil temp (4") 54°F
Watering Low
Pest pressure Low
Daylight 14.7 hrs
  1. Seed corn outdoors

    Mark the row. Birds and stray feet both have opinions about unmarked beds.

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Corn is a warm-season grass grown for its sweet ears, which are best eaten soon after harvest. It is wind-pollinated and must be planted in blocks for good kernel fill.

Somerset County, Maine is in USDA Zone 5a. The average last spring frost is May 22 and the first fall frost is September 26, giving you a growing season of approximately 127 days.

At an elevation of 356 feet, Somerset County receives approximately 48.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Corn to ensure they mature before fall.

Somerset County, ME (Zone 5a) Short season
127 days
Last Spring Frost May 22
127 growing days
First Fall Frost September 26
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Somerset County Soil Profile

Soil Type

Silt Loam

Soil pH

4.8-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (8 days to spare)
Transplant: May 15 🍅 Harvest: Jul 17 – Sep 11
Recommended (50%) ✓ Fits season (8 days to spare)
Transplant: May 22 🍅 Harvest: Jul 24 – Sep 18
Safe Start (90%) ✓ Fits season (11 days to spare)
Transplant: Jun 3 🍅 Harvest: Aug 5 – Sep 30

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 Somerset County

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

Soil pH

Your soil pH (4.8–6.4) is more acidic than Corn prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Corn.

Organic Matter

Organic matter is moderate (3.3%). Annual compost additions will help Corn.

How to Plant Corn

1"
Planting Depth
12"
Between Plants
36"
Between Rows

Succession Planting Corn

2
successive plantings in your 127-day season

Sow every 6.9 weeks. Last sowing by Jun 18 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.6″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Corn

Corn needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Corn Needs Rainfall You Supplement Action
Jan 2.9" 0" ❄️ Dormant
Feb 3.2" 0" ❄️ Dormant
Mar 4.5" 0" ❄️ Dormant
Apr 4.6" 0" ❄️ Dormant
May 6.5" 4.2" 2.3" 💧 Light watering
Jun 6.5" 5" 1.5" 💧 Light watering
Jul 6.5" 4" 2.5" 💧 Light watering
Aug 6.5" 4.6" 1.9" 💧 Light watering
Sep 6.5" 4" 2.5" 💧 Light watering
Oct 4.2" 0" ❄️ Dormant
Nov 3.8" 0" ❄️ Dormant
Dec 3.9" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Somerset County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Corn 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.

Corn needs ~800 GDD — county provides 1,270 GDD Excellent fit

Corn Planting Timeline — Somerset County, ME

Corn Planting Calendar

Activity When Date Range
Direct Sow May 29 May 29 – Jun 19
Harvest July 31 Jul 31 – Sep 25

Plant 1" deep · 12" apart · Rows 36" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Direct Sow
June Direct Sow
July Harvest
August Harvest
September Harvest
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · Natural rainfall sufficient

📅 Days to Maturity

60–100 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 5a

📆 Growing Season

127 days in Somerset County

Growing Tips for Corn in Somerset County

Direct sow Corn outdoors after May 22 in Somerset County when soil has warmed and frost danger has passed.

Common pests for Corn in this region include corn earworm and corn borers. Use row covers early in the season and inspect plants weekly.

General growing tips

Plant in blocks of at least 4 rows rather than single rows for proper pollination. Direct sow after soil reaches 60F. Side-dress with nitrogen when plants are knee-high.

Recommended Corn Varieties for Somerset County

Ultra-early corn varieties for your season

Earlivee (58d) Sugar Buns (72d) Early Sunglow (63d)

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Celery

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Corn in Somerset County, ME?

Somerset County is in Zone 5a with an average last frost of May 22. Plan your Corn planting based on this frost date — see the calendar above for exact timing.

What planting zone is Somerset County, ME?

Somerset County, Maine is in USDA Hardiness Zone 5a. The average last spring frost is May 22 and first fall frost is September 26.

🌱

Your Somerset County Garden Planner — Free

A 24-page printable planner built for Somerset County (Zone 5a). 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 Somerset County, ME. 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.