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When to Plant Cantaloupe in St. John's, NL

Cantaloupe is a sweet, aromatic melon with salmon-colored flesh and a netted rind. It requires a long, warm growing season and is the quintessential summer fruit.

St. John's, Newfoundland and Labrador is in USDA Zone 6a. The average last spring frost is April 23 and the first fall frost is October 20, giving you a growing season of approximately 180 days.

At an elevation of 246 feet, St. John's receives approximately 31.3 inches of rainfall annually with predominantly podzol soil. Summer highs average 79°F, so choose short-season varieties of Cantaloupe to ensure they mature before fall.

St. John's, NL (Zone 6a) Moderate season
180 days
Last Spring Frost April 23
180 growing days
First Fall Frost October 20

St. John's Soil Profile

Soil Type

Podzol

Soil pH

6.0-7.0

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (57 days to spare)
Transplant: May 6 🍅 Harvest: Jul 15 – Aug 19
Recommended (50%) ✓ Fits season (57 days to spare)
Transplant: May 6 🍅 Harvest: Jul 15 – Aug 19
Safe Start (90%) ✓ Fits season (57 days to spare)
Transplant: May 6 🍅 Harvest: Jul 15 – Aug 19

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.

How to Plant Cantaloupe

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

Plant Water Budget

Plant needs
1.3″/week
Rainfall provides
0.7″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 913 gal / 100 sq ft

Monthly Watering Guide for Cantaloupe

Cantaloupe needs approximately 1.3 inches of water per week (5.6" per month). Here's how your county's rainfall compares month by month.

Month Cantaloupe Needs Rainfall You Supplement Action
Jan 1.1" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 5.6" 2.9" 2.7" 💧 Light watering
May 5.6" 4" 1.6" 💧 Light watering
Jun 5.6" 3.8" 1.8" 💧 Light watering
Jul 5.6" 3.6" 2" 💧 Light watering
Aug 5.6" 3.4" 2.2" 💧 Light watering
Sep 5.6" 2.5" 3.1" 🚿 Regular watering
Oct 5.6" 2.7" 2.9" 🚿 Regular watering
Nov 1.9" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in St. John's). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Cantaloupe 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.

Cantaloupe needs ~740 GDD — county provides 1,665 GDD Excellent fit

Cantaloupe Planting Timeline — St. John's, NL

Cantaloupe Planting Calendar

Activity When Date Range
Transplant Outdoors May 14 May 14 – May 28
Harvest July 23 Jul 23 – Aug 27

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.3"/week · 1-2 times/week

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 6a

📆 Growing Season

180 days in St. John's

Growing Tips for Cantaloupe in St. John's

Common pests for Cantaloupe 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 on warm mounds. Reduce watering as fruits ripen. Harvest when stem slips easily from the fruit with gentle pressure.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cantaloupe in St. John's, NL?

St. John's is in Zone 6a with an average last frost of April 23. Plan your Cantaloupe planting based on this frost date — see the calendar above for exact timing.

What planting zone is St. John's, NL?

St. John's, Newfoundland and Labrador is in USDA Hardiness Zone 6a. The average last spring frost is April 23 and first fall frost is October 20.

🌱

Your St. John's Garden Planner — Free

A 24-page printable planner built for St. John's (Zone 6a). 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 St. John's, NL. Local conditions may vary. Last updated: April 2026.

Sources & credits

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