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When to Plant Calabash in Summit County, UT

Summit County, Utah Zone 5b May

Top priorities for Summit County, Utah gardeners in May

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

Avg. last frost June 10
Avg. first frost September 12
Soil temp (4") 33°F
Watering Moderate
Pest pressure Low
Daylight 14.3 hrs
To set up a strong June, finish these tasks
  • Transplants going out: calabash
  • Direct-sowing: calabash

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Calabash (bottle gourd) is a tropical vine producing edible young fruits used in Asian and African cooking. Mature dried fruits serve as natural containers and utensils.

Summit County, Utah is in USDA Zone 5b. 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 86°F, providing good warmth for Calabash during the growing season.

Summit County, UT (Zone 5b) Very short season
94 days
Last Spring Frost June 10
94 growing days
First Fall Frost September 12
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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 4 Transplant: Jun 13 🍅 Harvest: Sep 5 – Oct 31
Recommended (50%) ✗ May not fit
Start indoors: Apr 15 Transplant: Jun 24 🍅 Harvest: Sep 16 – Nov 11
Safe Start (90%) ✗ May not fit
Start indoors: Apr 26 Transplant: Jul 5 🍅 Harvest: Sep 27 – Nov 22

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 Calabash's growing requirements.

Soil pH

Your soil pH (6.4–8.3) overlaps with Calabash's range (6.0–7.5), though not a perfect match.

Soil Texture

The loam soil in Summit County is excellent for Calabash — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

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

How to Plant Calabash

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

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
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Calabash

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

Month Calabash Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 2.9" 0" ❄️ Dormant
May 2.9" 0" ❄️ Dormant
Jun 4.3" 1.8" 2.5" 🚿 Regular watering
Jul 4.3" 1.9" 2.4" 🚿 Regular watering
Aug 4.3" 2.5" 1.8" 💧 Light watering
Sep 4.3" 2" 2.3" 🚿 Regular watering
Oct 2.1" 0" ❄️ Dormant
Nov 2" 0" ❄️ Dormant
Dec 1.4" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Summit County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Calabash 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.

Calabash needs ~1,450 GDD — county provides 1,363 GDD Tight fit

Calabash Planting Timeline — Summit County, UT

Calabash Planting Calendar

Activity When Date Range
Start Indoors April 15 Apr 15 – Apr 29
Transplant Outdoors June 24 Jun 24 – Jul 8
Direct Sow June 17 Jun 17 – Jul 8
Harvest September 16 Sep 16 – Nov 11

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

80–120 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 5b

📆 Growing Season

94 days in Summit County

Growing Tips for Calabash in Summit County

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

Your 94.0-day growing season in Summit County is tight for Calabash (80.0-120.0 days to maturity). Start indoors and choose early-maturing varieties.

Common pests for Calabash 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. Calabash needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start seeds indoors 4 weeks early. Provide a very strong trellis for heavy fruits. Harvest young for cooking or let mature on the vine for crafts. Requires a long, warm season.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Calabash in Summit County, UT?

Summit County is in Zone 5b with an average last frost of June 10. Plan your Calabash planting based on this frost date — see the calendar above for exact timing.

What planting zone is Summit County, UT?

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

🌱

Your Summit County Garden Planner — Free

A 24-page printable planner built for Summit County (Zone 5b). 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 Summit County, UT. 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.