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When to plant Watermelon in Danforth, ME

Danforth's climate puts the Watermelon spring window between May 16 and June 6. time plantings around the expected last-frost window for best survival.

When to Plant Watermelon in Danforth, ME

Watermelon
Washington County, Maine Zone 5b July

Your July planting checklist for Washington County, Maine

Your garden in Washington County, Maine is working on a schedule, even when you're not. Here's where you should be this July.

Avg. last frost May 9
Avg. first frost October 7
Soil temp (4") 71°F
Watering Low
Pest pressure High
Daylight 15.1 hrs
A few tasks this July that'll pay off in August
  • First harvests: 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.

Danforth, Maine is in USDA Zone 5b. The average last spring frost is May 9 and the first fall frost is October 7, giving you a growing season of approximately 151 days.

At an elevation of 1,184 feet, Washington County receives approximately 43.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Watermelon to ensure they mature before fall.

Danforth, ME (Zone 5b) Moderate season
151 days
Last Spring Frost May 9
151 growing days
First Fall Frost October 7

Danforth Soil Profile

Soil Type

Silt Loam

Soil pH

5-6.5

Drainage

Well Drained

Watermelon Planting Risk Windows

Early Start (70% safe) ✓ Fits season (23 days to spare)
Start indoors: Mar 27 Transplant: May 15 🍅 Harvest: Jul 24 – Sep 11
Recommended (50%) ✓ Fits season (18 days to spare)
Start indoors: Apr 4 Transplant: May 23 🍅 Harvest: Aug 1 – Sep 19
Safe Start (90%) ✓ Fits season (25 days to spare)
Start indoors: Apr 22 Transplant: Jun 10 🍅 Harvest: Aug 19 – Oct 7

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 Danforth

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

Soil pH

Your soil pH (5.0–6.5) is more acidic than Watermelon prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.7%). 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 151-day season

Sow every 8 weeks. Last sowing by Jun 29 to harvest before frost.

Watermelon Water Budget

Plant needs
1.5″/week
Rainfall provides
1.2″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 375 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 3.2" 0" ❄️ Dormant
Feb 3" 0" ❄️ Dormant
Mar 4.1" 0" ❄️ Dormant
Apr 3.5" 0" ❄️ Dormant
May 6.5" 3.5" 3" 💧 Light watering
Jun 6.5" 4.7" 1.8" 💧 Light watering
Jul 6.5" 4.1" 2.4" 💧 Light watering
Aug 6.5" 4.1" 2.4" 💧 Light watering
Sep 6.5" 3.8" 2.7" 💧 Light watering
Oct 6.5" 3.4" 3.1" 💧 Light watering
Nov 3.4" 0" ❄️ Dormant
Dec 3.2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Washington 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 ~850 GDD — county provides 1,510 GDD Excellent fit

Watermelon Planting Timeline — Danforth, ME

Watermelon Planting Calendar

Activity When Date Range
Start Indoors April 4 Apr 4 – Apr 18
Transplant Outdoors May 23 May 23 – Jun 6
Direct Sow May 16 May 16 – Jun 6
Harvest August 1 Aug 1 – Sep 19

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · Only during dry spells

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 5b

📆 Growing Season

151 days in Washington County

Growing Tips for Watermelon in Danforth

Direct sow Watermelon outdoors after May 09 in Washington 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 Danforth

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 →

When should I plant Watermelon in Danforth, ME?

In Danforth, ME, plant Watermelon after the last frost (around May 9) and before the first frost (around October 7). Best results when soil holds above 50°F.

What growing zone is Danforth, ME for Watermelon?

Danforth sits in USDA Zone 5b. Watermelon grows reliably in zones 4a through 11b, so it's a good fit here.

Can Watermelon grow in Danforth's climate?

Yes — Watermelon grows well in Danforth's temperate climate. Danforth averages a 151-day frost-free season, with last frost around May 9 and first frost around October 7.

🌱

Your Washington County Garden Planner — Free

A 22-page printable planner built for Washington 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 Washington County, ME. Local conditions may vary. Last updated: July 2026.