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When to Plant Watermelon in Lincoln County, ME

Lincoln County, Maine Zone 5b April

Top priorities for Lincoln County, Maine gardeners in April

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

Avg. last frost May 3
Avg. first frost October 9
Soil temp (4") 46°F
Watering Low
Pest pressure Low
Daylight 13.2 hrs
Get ahead of May
  • Transplants going out: watermelon
  • Direct-sowing: watermelon

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Watermelon is a sprawling vine crop that produces sweet, juicy fruits in hot weather. Varieties range from personal-sized icebox types to 50-pound giants.

Lincoln County, Maine is in USDA Zone 5b. The average last spring frost is May 3 and the first fall frost is October 9, giving you a growing season of approximately 159 days.

At an elevation of 815 feet, Lincoln County receives approximately 50 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Watermelon during the growing season.

Lincoln County, ME (Zone 5b) Moderate season
159 days
Last Spring Frost May 3
159 growing days
First Fall Frost October 9

Lincoln County Soil Profile

Soil Type

Silt Loam

Soil pH

5-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (26 days to spare)
Start indoors: Mar 25 Transplant: May 13 🍅 Harvest: Jul 22 – Sep 9
Recommended (50%) ✓ Fits season (26 days to spare)
Start indoors: Mar 29 Transplant: May 17 🍅 Harvest: Jul 26 – Sep 13
Safe Start (90%) ✓ Fits season (29 days to spare)
Start indoors: Apr 11 Transplant: May 30 🍅 Harvest: Aug 8 – Sep 26

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 Lincoln County

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

Soil pH

Your soil pH (5.0–6.4) is more acidic than Watermelon prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Watermelon.

Organic Matter

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

How to Plant Watermelon

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Succession Planting Watermelon

2
successive plantings in your 159-day season

Sow every 8 weeks. Last sowing by Jul 01 to harvest before frost.

Plant Water Budget

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

Monthly Watering Guide for Watermelon

Watermelon 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 Watermelon Needs Rainfall You Supplement Action
Jan 3.6" 0" ❄️ Dormant
Feb 3.1" 0" ❄️ Dormant
Mar 4.6" 0" ❄️ Dormant
Apr 4.8" 0" ❄️ Dormant
May 6.5" 4.6" 1.9" 💧 Light watering
Jun 6.5" 4.6" 1.9" 💧 Light watering
Jul 6.5" 5.4" 1.1" 💧 Light watering
Aug 6.5" 4.2" 2.3" 💧 Light watering
Sep 6.5" 4.1" 2.4" 💧 Light watering
Oct 6.5" 3.9" 2.6" 💧 Light watering
Nov 3.4" 0" ❄️ Dormant
Dec 3.8" 0" ❄️ Dormant

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

Watermelon 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.

Watermelon needs ~1,296 GDD — county provides 2,424 GDD Excellent fit

Watermelon Planting Timeline — Lincoln County, ME

Watermelon Planting Calendar

Activity When Date Range
Start Indoors March 29 Mar 29 – Apr 12
Transplant Outdoors May 17 May 17 – May 31
Direct Sow May 10 May 10 – May 31
Harvest July 26 Jul 26 – Sep 13

Plant 1" deep · 30" apart · Rows 42" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · Natural rainfall sufficient

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 5b

📆 Growing Season

159 days in Lincoln County

Growing Tips for Watermelon in Lincoln County

Direct sow Watermelon outdoors after May 03 in Lincoln County when soil has warmed and frost danger has passed.

Common pests for Watermelon in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 3-4 weeks early or direct sow after soil is warm. Plant on mounds with plenty of space. Check ripeness by looking for a yellow ground spot and dull thump when tapped.

Recommended Watermelon Varieties for Lincoln County

Compact, early melons for shorter seasons

Sugar Baby (75d) Blacktail Mountain (70d) Golden Midget (70d)

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Watermelon in Lincoln County, ME?

Lincoln County is in Zone 5b with an average last frost of May 3. Plan your Watermelon planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lincoln County, ME?

Lincoln County, Maine is in USDA Hardiness Zone 5b. The average last spring frost is May 3 and first fall frost is October 9.

🌱

Your Lincoln County Garden Planner — Free

A 24-page printable planner built for Lincoln County (Zone 5b). 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 Lincoln County, ME. Local conditions may vary. Last updated: April 2026.

Sources & credits

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