Blog

When to Plant Zucchini in Summit County, UT

Zucchini is an incredibly prolific summer squash that can produce an abundance of fruit from just a few plants. It is versatile in the kitchen from grilling to baking.

Summit County, Utah is in USDA Zone 5a. The average last spring frost is June 10 and the first fall frost is September 12, giving you a growing season of approximately 94 days.

At an elevation of 8,145 feet, Summit County receives approximately 24.8 inches of rainfall annually with predominantly loam soil. Summer highs average 86ยฐF, providing good warmth for Zucchini during the growing season.

Summit County, UT (Zone 5a) Very short season
94 days
Last Spring Frost June 10
94 growing days
First Fall Frost September 12

Summit County Soil Profile

Soil Type

Loam

Soil pH

6.4-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 25 Transplant: Jun 13 🍅 Harvest: Aug 1 – Sep 26
Recommended (50%) ✗ May not fit
Start indoors: May 6 Transplant: Jun 24 🍅 Harvest: Aug 12 – Oct 7
Safe Start (90%) ✗ May not fit
Start indoors: May 17 Transplant: Jul 5 🍅 Harvest: Aug 23 – Oct 18

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 Summit County

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

Soil pH

Your soil pH (6.4โ€“8.3) overlaps with Zucchini's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

The loam soil in Summit County is excellent for Zucchini โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Zucchini.

How to Plant Zucchini

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

Succession Planting Zucchini

2
successive plantings in your 94-day season

Sow every 5.1 weeks. Last sowing by Jul 14 to harvest before frost.

Plant Water Budget

Plant needs
1.2″/week
Rainfall provides
1.1″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 92 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Zucchini

Zucchini needs approximately 1.2 inches of water per week (5.2" per month). Here's how your county's rainfall compares month by month.

Month Zucchini Needs Rainfall You Supplement Action
Jan โ€” 1.6" 0" โ„๏ธ Dormant
Feb โ€” 1.3" 0" โ„๏ธ Dormant
Mar โ€” 2.4" 0" โ„๏ธ Dormant
Apr โ€” 2.9" 0" โ„๏ธ Dormant
May โ€” 2.9" 0" โ„๏ธ Dormant
Jun 5.2" 1.8" 3.4" ๐Ÿšฟ Regular watering
Jul 5.2" 1.9" 3.3" ๐Ÿšฟ Regular watering
Aug 5.2" 2.5" 2.7" ๐Ÿšฟ Regular watering
Sep 5.2" 2" 3.2" ๐Ÿšฟ Regular watering
Oct โ€” 2.1" 0" โ„๏ธ Dormant
Nov โ€” 2" 0" โ„๏ธ Dormant
Dec โ€” 1.4" 0" โ„๏ธ Dormant

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

Zucchini 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.

Zucchini needs ~761 GDD — county provides 1,363 GDD Excellent fit

Zucchini Planting Timeline โ€” Summit County, UT

Zucchini Planting Calendar

Activity When Date Range
Start Indoors May 6 May 6 โ€“ May 20
Transplant Outdoors June 24 Jun 24 โ€“ Jul 8
Direct Sow June 17 Jun 17 โ€“ Jul 8
Harvest August 12 Aug 12 โ€“ Oct 7

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.2"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

45โ€“60 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 5a

๐Ÿ“† Growing Season

94 days in Summit County

Growing Tips for Zucchini in Summit County

Direct sow Zucchini outdoors after June 10 in Summit County when soil has warmed and frost danger has passed.

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

Summit County receives only 25" of rain annually. Zucchini needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow after last frost. Harvest when fruits are 6-8 inches long for best flavor and texture. Check plants daily in summer as fruits can double in size overnight.

Recommended Zucchini Varieties for Summit County

Quick-producing varieties for shorter seasons

Black Beauty (50d) Raven (48d) Eight Ball (40d)

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Zucchini in Summit County, UT?

Summit County is in Zone 5a with an average last frost of June 10. Plan your Zucchini planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Summit County, UT?

Summit County, Utah is in USDA Hardiness Zone 5a. The average last spring frost is June 10 and first fall frost is September 12.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Summit County gardeners in Zone 5a 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 Summit County, UT. Local conditions may vary. Last updated: April 2026.