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When to Plant Calabash in Cass County, IL

Cass County, Illinois Zone 6a May

May in the garden — Cass County, Illinois

Here's what deserves your attention in Cass County, Illinois this month. Everything below is tailored to Zone 6a and timed around your local frost dates.

Avg. last frost April 15
Avg. first frost October 16
Soil temp (4") 58°F
Watering Moderate
Pest pressure Low
Daylight 14.2 hrs
Get ahead of June
  • Starting indoors: 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.

Cass County, Illinois is in USDA Zone 6a. The average last spring frost is April 15 and the first fall frost is October 16, giving you a growing season of approximately 184 days.

At an elevation of 703 feet, Cass County receives approximately 31.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Calabash to ensure they mature before fall.

Cass County, IL (Zone 6a) Moderate season
184 days
Last Spring Frost April 15
184 growing days
First Fall Frost October 16

Cass County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (30 days to spare)
Start indoors: Feb 12 Transplant: Apr 23 🍅 Harvest: Jul 16 – Sep 10
Recommended (50%) ✓ Fits season (30 days to spare)
Start indoors: Feb 18 Transplant: Apr 29 🍅 Harvest: Jul 22 – Sep 16
Safe Start (90%) ✓ Fits season (28 days to spare)
Start indoors: Mar 5 Transplant: May 14 🍅 Harvest: Aug 6 – Oct 1

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 Cass County

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

Soil pH

Your soil pH (6.0–7.2) is within Calabash's preferred range (6.0–7.5).

Soil Texture

The silt loam soil in Cass 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 (4.0%). Annual compost additions will help Calabash.

How to Plant Calabash

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

Succession Planting Calabash

2
successive plantings in your 184-day season

Sow every 9.1 weeks. Last sowing by Jun 18 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 1,124 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 1.4" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 4.3" 2.8" 1.5" 💧 Light watering
May 4.3" 3.6" 0.7" 💧 Light watering
Jun 4.3" 3.7" 0.6" 💧 Light watering
Jul 4.3" 3.3" 1" 💧 Light watering
Aug 4.3" 3.8" 0.5" 💧 Light watering
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 2.6" 1.7" 💧 Light watering
Nov 2" 0" ❄️ Dormant
Dec 1.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Cass 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 ~1,225 GDD — county provides 2,254 GDD Excellent fit

Calabash Planting Timeline — Cass County, IL

Calabash Planting Calendar

Activity When Date Range
Start Indoors February 18 Feb 18 – Mar 4
Transplant Outdoors April 29 Apr 29 – May 13
Direct Sow April 22 Apr 22 – May 13
Harvest July 22 Jul 22 – Sep 16

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

80–120 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 6a

📆 Growing Season

184 days in Cass County

Growing Tips for Calabash in Cass County

Direct sow Calabash outdoors after April 15 in Cass 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 Cass County, IL?

Cass County is in Zone 6a with an average last frost of April 15. Plan your Calabash planting based on this frost date — see the calendar above for exact timing.

What planting zone is Cass County, IL?

Cass County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 15 and first fall frost is October 16.

🌱

Your Cass County Garden Planner — Free

A 24-page printable planner built for Cass County (Zone 6a). 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 Cass County, IL. 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.