When to Plant Watermelon in New London County, CT
New London County, Connecticut gardeners: here's your May plan
We've pulled the most time-sensitive tasks for New London County, Connecticut this May and put them front and centre. Tackle them in order.
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Time to transplant watermelon
Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.
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Sow watermelon in trays indoors
These need a head start before your last frost (April 23). Sow into cells now so you're ready to transplant in a few weeks.
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.
New London County, Connecticut is in USDA Zone 7a. The average last spring frost is April 23 and the first fall frost is October 18, giving you a growing season of approximately 178 days.
At an elevation of 766 feet, New London County receives approximately 49.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Watermelon during the growing season.
New London County Soil Profile
Soil Type
Silt Loam
Soil pH
5-6.6
Drainage
Well Drained
Plant Planting Risk Windows
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 New London County
How your county's soil matches Watermelon's growing requirements.
Soil pH
Your soil pH (5.0–6.6) is more acidic than Watermelon prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in New London 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 (3.6%). Annual compost additions will help Watermelon.
How to Plant Watermelon
Succession Planting Watermelon
Sow every 8 weeks. Last sowing by Jul 10 to harvest before frost.
Plant Water Budget
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 | — | 3.5" | 0" | ❄️ Dormant |
| Feb | — | 3.5" | 0" | ❄️ Dormant |
| Mar | — | 4" | 0" | ❄️ Dormant |
| Apr | 6.5" | 4.7" | 1.8" | 💧 Light watering |
| May | 6.5" | 4.4" | 2.1" | 💧 Light watering |
| Jun | 6.5" | 4.3" | 2.2" | 💧 Light watering |
| Jul | 6.5" | 5.1" | 1.4" | 💧 Light watering |
| Aug | 6.5" | 3.9" | 2.6" | 💧 Light watering |
| Sep | 6.5" | 4.1" | 2.4" | 💧 Light watering |
| Oct | 6.5" | 4.5" | 2" | 💧 Light watering |
| Nov | — | 3.9" | 0" | ❄️ Dormant |
| Dec | — | 3.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in New London 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 Planting Timeline — New London County, CT
Watermelon Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 26 | Mar 26 – Apr 9 |
| Transplant Outdoors | May 7 | May 7 – May 21 |
| Direct Sow | April 30 | Apr 30 – May 21 |
| Harvest | July 16 | Jul 16 – Sep 3 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Direct Sow |
| 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 7a
📆 Growing Season
178 days in New London County
Growing Tips for Watermelon in New London County
Direct sow Watermelon outdoors after April 23 in New London 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.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Watermelon in Other Locations
Frequently Asked Questions
When should I plant Watermelon in New London County, CT?
New London County is in Zone 7a with an average last frost of April 23. Plan your Watermelon planting based on this frost date — see the calendar above for exact timing.
What planting zone is New London County, CT?
New London County, Connecticut is in USDA Hardiness Zone 7a. The average last spring frost is April 23 and first fall frost is October 18.
Your New London County Garden Planner — Free
A 24-page printable planner built for New London County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.