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When to Plant Lettuce in Oxford County, ME

Oxford County, Maine Zone 5a May

Oxford County, Maine gardeners: here's your May plan

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Oxford County, Maine.

Avg. last frost May 16
Avg. first frost September 29
Soil temp (4") 56°F
Watering Low
Pest pressure Low
Daylight 14.6 hrs
  1. Harden off and plant lettuce

    Your last frost (May 16) has passed. These warm-season crops can handle outdoor soil now.

  2. Sow lettuce where they'll grow

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

Get ahead of June
  • Starting indoors: lettuce
  • First harvests: lettuce

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Lettuce is a fast-growing cool-season green available in leaf, romaine, butterhead, and crisphead types. It is the foundation of salads and one of the easiest crops to grow.

Oxford County, Maine is in USDA Zone 5a. The average last spring frost is May 16 and the first fall frost is September 29, giving you a growing season of approximately 136 days.

At an elevation of 186 feet, Oxford County receives approximately 39.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 82°F, so choose short-season varieties of Lettuce to ensure they mature before fall.

Oxford County, ME (Zone 5a) Short season
136 days
Last Spring Frost May 16
136 growing days
First Fall Frost September 29

Oxford County Soil Profile

Soil Type

Silt Loam

Soil pH

4.9-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (28 days to spare)
Start indoors: Apr 6 Transplant: May 11 🍅 Harvest: Jun 15 – Aug 24
Recommended (50%) ✓ Fits season (31 days to spare)
Start indoors: Apr 11 Transplant: May 16 🍅 Harvest: Jun 20 – Aug 29
Safe Start (90%) ✓ Fits season (34 days to spare)
Start indoors: Apr 25 Transplant: May 30 🍅 Harvest: Jul 4 – Sep 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 Oxford County

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

Soil pH

Your soil pH (4.9–6.4) is more acidic than Lettuce prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Lettuce.

Organic Matter

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

How to Plant Lettuce

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Lettuce

5
successive plantings in your 136-day season

Sow every 3.4 weeks. Last sowing by Jul 31 to harvest before frost.

For a dedicated fall crop, sow by Jul 21.

Plant Water Budget

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

Monthly Watering Guide for Lettuce

Lettuce needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Lettuce Needs Rainfall You Supplement Action
Jan 2.7" 0" ❄️ Dormant
Feb 2.8" 0" ❄️ Dormant
Mar 3.5" 0" ❄️ Dormant
Apr 3.7" 0" ❄️ Dormant
May 3" 3.8" 0" ✅ Rainfall sufficient
Jun 3" 3.6" 0" ✅ Rainfall sufficient
Jul 3" 3.7" 0" ✅ Rainfall sufficient
Aug 3" 3.6" 0" ✅ Rainfall sufficient
Sep 3" 3.3" 0" ✅ Rainfall sufficient
Oct 2.8" 0" ❄️ Dormant
Nov 3.4" 0" ❄️ Dormant
Dec 3" 0" ❄️ Dormant

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

Lettuce 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.

Lettuce needs ~518 GDD — county provides 1,564 GDD Excellent fit

Lettuce Planting Timeline — Oxford County, ME

Lettuce Planting Calendar

Activity When Date Range
Start Indoors April 11 Apr 11 – Apr 25
Transplant Outdoors May 16 May 16 – May 30
Direct Sow May 2 May 2 – May 23
Harvest June 20 Jun 20 – Aug 29
Fall Sowing July 21 Jul 21 – Aug 4

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.7"/week · Natural rainfall sufficient

📅 Days to Maturity

30–60 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 5a

📆 Growing Season

136 days in Oxford County

Growing Tips for Lettuce in Oxford County

Direct sow Lettuce outdoors after May 16 in Oxford County when soil has warmed and frost danger has passed.

Common pests for Lettuce in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Sow seeds directly every 2 weeks for continuous harvest. Provide afternoon shade in warm weather to delay bolting. Harvest in the morning for crispest leaves.

Companion Planting

Good Companions

Avoid Planting Near

  • Celery

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Lettuce Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Let plants bolt and flower. Harvest seed heads when fluffy.
Storage Store airtight; viable 6 years at 35°F, under 45% humidity.

Very easy to save. Let a few plants bolt each season.

Frequently Asked Questions

When should I plant Lettuce in Oxford County, ME?

Oxford County is in Zone 5a with an average last frost of May 16. Plan your Lettuce planting based on this frost date — see the calendar above for exact timing.

What planting zone is Oxford County, ME?

Oxford County, Maine is in USDA Hardiness Zone 5a. The average last spring frost is May 16 and first fall frost is September 29.

🌱

Your Oxford County Garden Planner — Free

A 24-page printable planner built for Oxford 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.

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 Oxford 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.