Blog

When to Plant Squash (Summer) in Middlesex County, CT

Summer squash includes zucchini, yellow crookneck, and pattypan varieties that are harvested young and tender. They are prolific producers in warm weather.

Middlesex County, Connecticut is in USDA Zone 6b. The average last spring frost is April 18 and the first fall frost is October 26, giving you a growing season of approximately 191 days.

At an elevation of 248 feet, Middlesex County receives approximately 40.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90ยฐF, providing good warmth for Squash (Summer) during the growing season.

Middlesex County, CT (Zone 6b) Moderate season
191 days
Last Spring Frost April 18
191 growing days
First Fall Frost October 26

Middlesex County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (64 days to spare)
Start indoors: Mar 7 Transplant: Apr 25 🍅 Harvest: Jun 13 – Aug 15
Recommended (50%) ✓ Fits season (65 days to spare)
Start indoors: Mar 14 Transplant: May 2 🍅 Harvest: Jun 20 – Aug 22
Safe Start (90%) ✓ Fits season (57 days to spare)
Start indoors: Apr 1 Transplant: May 20 🍅 Harvest: Jul 8 – Sep 9

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 Middlesex County

How your county's soil matches Squash (Summer)'s growing requirements.

Soil pH

Your soil pH (5.2โ€“6.2) is more acidic than Squash (Summer) prefers (6.0โ€“7.5). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Middlesex County is excellent for Squash (Summer) โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

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

How to Plant Squash (Summer)

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

Succession Planting Squash (Summer)

5
successive plantings in your 191-day season

Sow every 5.1 weeks. Last sowing by Aug 22 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 190 gal / 100 sq ft

Monthly Watering Guide for Squash (Summer)

Squash (Summer) needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Squash (Summer) Needs Rainfall You Supplement Action
Jan โ€” 3.2" 0" โ„๏ธ Dormant
Feb โ€” 3" 0" โ„๏ธ Dormant
Mar โ€” 3.7" 0" โ„๏ธ Dormant
Apr 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
May 4.3" 3.9" 0.4" ๐Ÿ’ง Light watering
Jun 4.3" 4.3" 0" โœ… Rainfall sufficient
Jul 4.3" 3.4" 0.9" ๐Ÿ’ง Light watering
Aug 4.3" 3.8" 0.5" ๐Ÿ’ง Light watering
Sep 4.3" 3" 1.3" ๐Ÿ’ง Light watering
Oct 4.3" 3" 1.3" ๐Ÿ’ง Light watering
Nov โ€” 2.8" 0" โ„๏ธ Dormant
Dec โ€” 2.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Middlesex County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Squash (Summer) 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" โ€” every day above 50ยฐF 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.

Squash (Summer) needs ~962 GDD — county provides 3,342 GDD Excellent fit

Squash (Summer) Planting Timeline โ€” Middlesex County, CT

Squash (Summer) Planting Calendar

Activity When Date Range
Start Indoors March 14 Mar 14 โ€“ Mar 28
Transplant Outdoors May 2 May 2 โ€“ May 16
Direct Sow April 25 Apr 25 โ€“ May 16
Harvest June 20 Jun 20 โ€“ Aug 22

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

45โ€“65 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 6b

๐Ÿ“† Growing Season

191 days in Middlesex County

Growing Tips for Squash (Summer) in Middlesex County

Direct sow Squash (Summer) outdoors after April 18 in Middlesex County when soil has warmed and frost danger has passed.

Your generous 191.0-day season in Middlesex County allows multiple plantings of Squash (Summer). Sow every 22.0 days for continuous harvest.

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

General growing tips

Direct sow after last frost on mounds. Harvest frequently when fruits are 6-8 inches for best texture. Check plants daily as they grow rapidly in summer heat.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Squash (Summer) in Middlesex County, CT?

Middlesex County is in Zone 6b with an average last frost of April 18. Plan your Squash (Summer) planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Middlesex County, CT?

Middlesex County, Connecticut is in USDA Hardiness Zone 6b. The average last spring frost is April 18 and first fall frost is October 26.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Middlesex County gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Middlesex County, CT. Local conditions may vary. Last updated: April 2026.