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When to Plant Hubbard Squash in Callahan County, TX

Hubbard squash is a large, bumpy-skinned winter squash with dense, sweet, dry flesh ideal for baking and pies. The hard shell allows storage for 6 months or more.

Callahan County, Texas is in USDA Zone 7b. The average last spring frost is March 21 and the first fall frost is November 16, giving you a growing season of approximately 240 days.

At an elevation of 4,241 feet, Callahan County receives approximately 59.1 inches of rainfall annually with predominantly loam soil. Summer highs average 91ยฐF, providing good warmth for Hubbard Squash during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Hubbard Squash root diseases.

Callahan County, TX (Zone 7b) Long season
240 days
Last Spring Frost March 21
240 growing days
First Fall Frost November 16

Callahan County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (90 days to spare)
Start indoors: Feb 10 Transplant: Mar 24 🍅 Harvest: Jul 7 – Aug 11
Recommended (50%) ✓ Fits season (86 days to spare)
Start indoors: Feb 21 Transplant: Apr 4 🍅 Harvest: Jul 18 – Aug 22
Safe Start (90%) ✓ Fits season (81 days to spare)
Start indoors: Mar 15 Transplant: Apr 26 🍅 Harvest: Aug 9 – Sep 13

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 Callahan County

How your county's soil matches Hubbard Squash's growing requirements.

Soil pH

Your soil pH (6.8โ€“7.4) is more alkaline than Hubbard Squash prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Hubbard Squash.

How to Plant Hubbard Squash

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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Hubbard Squash

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

Month Hubbard Squash Needs Rainfall You Supplement Action
Jan โ€” 1.7" 0" โ„๏ธ Dormant
Feb โ€” 1.9" 0" โ„๏ธ Dormant
Mar 4.3" 3.3" 1" ๐Ÿ’ง Light watering
Apr 4.3" 5.9" 0" โœ… Rainfall sufficient
May 4.3" 7.8" 0" โœ… Rainfall sufficient
Jun 4.3" 11" 0" โœ… Rainfall sufficient
Jul 4.3" 8.5" 0" โœ… Rainfall sufficient
Aug 4.3" 6.1" 0" โœ… Rainfall sufficient
Sep 4.3" 5.7" 0" โœ… Rainfall sufficient
Oct 4.3" 3.8" 0.5" ๐Ÿ’ง Light watering
Nov 4.3" 1.8" 2.5" ๐Ÿšฟ Regular watering
Dec โ€” 1.7" 0" โ„๏ธ Dormant

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

Hubbard Squash 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.

Hubbard Squash needs ~2,008 GDD — county provides 4,380 GDD Excellent fit

Hubbard Squash Planting Timeline โ€” Callahan County, TX

Hubbard Squash Planting Calendar

Activity When Date Range
Start Indoors February 21 Feb 21 โ€“ Mar 7
Transplant Outdoors April 4 Apr 4 โ€“ Apr 18
Direct Sow March 28 Mar 28 โ€“ Apr 18
Harvest July 18 Jul 18 โ€“ Aug 22

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

100โ€“120 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 7b

๐Ÿ“† Growing Season

240 days in Callahan County

Growing Tips for Hubbard Squash in Callahan County

Direct sow Hubbard Squash outdoors after March 21 in Callahan County when soil has warmed and frost danger has passed.

Common pests for Hubbard Squash 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 in short-season areas. Requires ample space and rich soil. Harvest when the skin is very hard and the color is deep. Cure in the sun before storing.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Hubbard Squash in Callahan County, TX?

Callahan County is in Zone 7b with an average last frost of March 21. Plan your Hubbard Squash planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Callahan County, TX?

Callahan County, Texas is in USDA Hardiness Zone 7b. The average last spring frost is March 21 and first fall frost is November 16.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Callahan County gardeners in Zone 7b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

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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 Callahan County, TX. Local conditions may vary. Last updated: April 2026.