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When to Plant Calabash in Washington County, WI

Washington County, Wisconsin Zone 5a April

April to-do list for Washington County, Wisconsin

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

Avg. last frost April 27
Avg. first frost October 11
Soil temp (4") 45°F
Watering Moderate
Pest pressure Low
Daylight 13.2 hrs
A few tasks this April that'll pay off in May
  • 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.

Washington County, Wisconsin is in USDA Zone 5a. The average last spring frost is April 27 and the first fall frost is October 11, giving you a growing season of approximately 167 days.

At an elevation of 1,141 feet, Washington County receives approximately 33.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Calabash during the growing season.

Washington County, WI (Zone 5a) Moderate season
167 days
Last Spring Frost April 27
167 growing days
First Fall Frost October 11

Washington County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (10 days to spare)
Start indoors: Feb 27 Transplant: May 8 🍅 Harvest: Jul 31 – Sep 25
Recommended (50%) ✓ Fits season (13 days to spare)
Start indoors: Mar 2 Transplant: May 11 🍅 Harvest: Aug 3 – Sep 28
Safe Start (90%) ✓ Fits season (11 days to spare)
Start indoors: Mar 18 Transplant: May 27 🍅 Harvest: Aug 19 – Oct 14

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 Washington County

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

Soil pH

Your soil pH (6.1–6.7) is within Calabash's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.3%) — Calabash will thrive.

How to Plant Calabash

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

Succession Planting Calabash

2
successive plantings in your 167-day season

Sow every 9.1 weeks. Last sowing by Jun 13 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 227 gal / 100 sq ft

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 1.5" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 4.3" 3.5" 0.8" 💧 Light watering
May 4.3" 3.5" 0.8" 💧 Light watering
Jun 4.3" 4.2" 0.1" 💧 Light watering
Jul 4.3" 3.3" 1" 💧 Light watering
Aug 4.3" 4" 0.3" 💧 Light watering
Sep 4.3" 2.8" 1.5" 💧 Light watering
Oct 4.3" 3" 1.3" 💧 Light watering
Nov 2.2" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Washington 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 ~1,375 GDD — county provides 2,296 GDD Excellent fit

Calabash Planting Timeline — Washington County, WI

Calabash Planting Calendar

Activity When Date Range
Start Indoors March 2 Mar 2 – Mar 16
Transplant Outdoors May 11 May 11 – May 25
Direct Sow May 4 May 4 – May 25
Harvest August 3 Aug 3 – Sep 28

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

80–120 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 5a

📆 Growing Season

167 days in Washington County

Growing Tips for Calabash in Washington County

Direct sow Calabash outdoors after April 27 in Washington 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.

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 Washington County, WI?

Washington County is in Zone 5a with an average last frost of April 27. Plan your Calabash planting based on this frost date — see the calendar above for exact timing.

What planting zone is Washington County, WI?

Washington County, Wisconsin is in USDA Hardiness Zone 5a. The average last spring frost is April 27 and first fall frost is October 11.

🌱

Your Washington County Garden Planner — Free

A 24-page printable planner built for Washington 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 Washington County, WI. Local conditions may vary. Last updated: April 2026.

Sources & credits

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