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When to Plant Squash (Summer) in Chittenden County, VT

Chittenden County, Vermont Zone 5a May

May in the garden — Chittenden County, Vermont

May is a pivotal month for Chittenden County, Vermont gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 12
Avg. first frost October 5
Soil temp (4") 53°F
Watering Moderate
Pest pressure Low
Daylight 14.6 hrs
  1. Move squash (summer) from tray to bed

    Your last frost (May 12) has passed. These warm-season crops can handle outdoor soil now.

  2. Put squash (summer) seeds straight in the ground

    Thin ruthlessly once seedlings are up. Crowded roots mean smaller crops from every plant.

A few tasks this May that'll pay off in June
  • Starting indoors: squash (summer)

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

Chittenden County, Vermont is in USDA Zone 5a. The average last spring frost is May 12 and the first fall frost is October 5, giving you a growing season of approximately 146 days.

At an elevation of 235 feet, Chittenden County receives approximately 38.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 82°F, so choose short-season varieties of Squash (Summer) to ensure they mature before fall.

Chittenden County, VT (Zone 5a) Short season
146 days
Last Spring Frost May 12
146 growing days
First Fall Frost October 5

Chittenden County Soil Profile

Soil Type

Silt Loam

Soil pH

4.8-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (14 days to spare)
Start indoors: Apr 1 Transplant: May 20 🍅 Harvest: Jul 8 – Sep 9
Recommended (50%) ✓ Fits season (20 days to spare)
Start indoors: Apr 7 Transplant: May 26 🍅 Harvest: Jul 14 – Sep 15
Safe Start (90%) ✓ Fits season (17 days to spare)
Start indoors: Apr 27 Transplant: Jun 15 🍅 Harvest: Aug 3 – Oct 5

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 Chittenden County

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

Soil pH

Your soil pH (4.8–6.3) is more acidic than Squash (Summer) prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Chittenden County is excellent for Squash (Summer) — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.2%). 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)

3
successive plantings in your 146-day season

Sow every 5.1 weeks. Last sowing by Aug 01 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 2.5" 0" ❄️ Dormant
Feb 2.4" 0" ❄️ Dormant
Mar 3.5" 0" ❄️ Dormant
Apr 3" 0" ❄️ Dormant
May 4.3" 3.1" 1.2" 💧 Light watering
Jun 4.3" 3.8" 0.5" 💧 Light watering
Jul 4.3" 4.1" 0.2" 💧 Light watering
Aug 4.3" 4" 0.3" 💧 Light watering
Sep 4.3" 3.5" 0.8" 💧 Light watering
Oct 4.3" 3.6" 0.7" 💧 Light watering
Nov 2.7" 0" ❄️ Dormant
Dec 2.5" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Chittenden County). Supplement amounts are based on average rainfall — 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" — 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.

Squash (Summer) needs ~632 GDD — county provides 1,679 GDD Excellent fit

Squash (Summer) Planting Timeline — Chittenden County, VT

Squash (Summer) Planting Calendar

Activity When Date Range
Start Indoors April 7 Apr 7 – Apr 21
Transplant Outdoors May 26 May 26 – Jun 9
Direct Sow May 19 May 19 – Jun 9
Harvest July 14 Jul 14 – Sep 15

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 Harvest
August Harvest
September Harvest
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

45–65 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 5a

📆 Growing Season

146 days in Chittenden County

Growing Tips for Squash (Summer) in Chittenden County

Direct sow Squash (Summer) outdoors after May 12 in Chittenden County when soil has warmed and frost danger has passed.

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 Chittenden County, VT?

Chittenden County is in Zone 5a with an average last frost of May 12. Plan your Squash (Summer) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Chittenden County, VT?

Chittenden County, Vermont is in USDA Hardiness Zone 5a. The average last spring frost is May 12 and first fall frost is October 5.

🌱

Your Chittenden County Garden Planner — Free

A 24-page printable planner built for Chittenden County (Zone 5a). 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 Chittenden County, VT. Local conditions may vary. Last updated: May 2026.

Sources & credits

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