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When to Plant Calabash in Blaine County, ID

Blaine County, Idaho Zone 5b May

Blaine County, Idaho gardeners: here's your May plan

Welcome to May in Zone 5b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost May 18
Avg. first frost October 3
Soil temp (4") 35°F
Watering High
Pest pressure Low
Daylight 14.5 hrs
  1. Sow calabash where they'll grow

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

June will be here before you know it — start on
  • Transplants going out: 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.

Blaine County, Idaho is in USDA Zone 5b. The average last spring frost is May 18 and the first fall frost is October 3, giving you a growing season of approximately 138 days.

At an elevation of 7,128 feet, Blaine County receives approximately 17.7 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Calabash to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Calabash successfully. Mulch heavily to conserve soil moisture.

Blaine County, ID (Zone 5b) Short season
138 days
Last Spring Frost May 18
138 growing days
First Fall Frost October 3
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Blaine County Soil Profile

Soil Type

Loam

Soil pH

6.7-8.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 11 Transplant: May 20 🍅 Harvest: Aug 12 – Oct 7
Recommended (50%) ✗ May not fit
Start indoors: Mar 23 Transplant: Jun 1 🍅 Harvest: Aug 24 – Oct 19
Safe Start (90%) ✗ May not fit
Start indoors: Apr 16 Transplant: Jun 25 🍅 Harvest: Sep 17 – Nov 12

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 Blaine County

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

Soil pH

Your soil pH (6.7–8.4) is more alkaline than Calabash prefers (6.0–7.5). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Calabash.

Organic Matter

Organic matter is moderate (2.2%). 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
0.5″/week
You supply
0.9″/week
Watering frequency 2-3 times/week
Season total 1,122 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 1.4" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 1.7" 0" ❄️ Dormant
May 4.3" 1.9" 2.4" 🚿 Regular watering
Jun 4.3" 1.2" 3.1" 🚿 Regular watering
Jul 4.3" 1.8" 2.5" 🚿 Regular watering
Aug 4.3" 2.2" 2.1" 💧 Light watering
Sep 4.3" 1.5" 2.8" 🚿 Regular watering
Oct 4.3" 1.4" 2.9" 🚿 Regular watering
Nov 1.3" 0" ❄️ Dormant
Dec 1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Blaine 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 ~1,300 GDD — county provides 1,794 GDD Excellent fit

Calabash Planting Timeline — Blaine County, ID

Calabash Planting Calendar

Activity When Date Range
Start Indoors March 23 Mar 23 – Apr 6
Transplant Outdoors June 1 Jun 1 – Jun 15
Direct Sow May 25 May 25 – Jun 15
Harvest August 24 Aug 24 – Oct 19

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

80–120 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5b

📆 Growing Season

138 days in Blaine County

Growing Tips for Calabash in Blaine County

Direct sow Calabash outdoors after May 18 in Blaine County when soil has warmed and frost danger has passed.

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.

Blaine County receives only 18" 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 Blaine County, ID?

Blaine County is in Zone 5b with an average last frost of May 18. Plan your Calabash planting based on this frost date — see the calendar above for exact timing.

What planting zone is Blaine County, ID?

Blaine County, Idaho is in USDA Hardiness Zone 5b. The average last spring frost is May 18 and first fall frost is October 3.

🌱

Your Blaine County Garden Planner — Free

A 24-page printable planner built for Blaine 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 Blaine County, ID. 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.