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When to Plant Squash (Winter) in Williamson County, TX

Williamson County, Texas Zone 9a May

This month in Williamson County, Texas

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Williamson County, Texas.

Avg. last frost March 5
Avg. first frost November 22
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 13.6 hrs
To set up a strong June, finish these tasks
  • First harvests: squash (winter)

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Winter squash includes butternut, acorn, delicata, and hubbard varieties grown to full maturity with hard rinds for storage. They develop sweet, dense flesh.

Williamson County, Texas is in USDA Zone 9a. The average last spring frost is March 5 and the first fall frost is November 22, giving you a growing season of approximately 262 days.

At an elevation of 1,023 feet, Williamson County receives approximately 53.3 inches of rainfall annually with predominantly clay soil. Summer highs average 94°F, providing good warmth for Squash (Winter) during the growing season. Clay soil retains moisture well for Squash (Winter), but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Squash (Winter) root diseases.

Williamson County, TX (Zone 9a) Long season
262 days
Last Spring Frost March 5
262 growing days
First Fall Frost November 22

Williamson County Soil Profile

Soil Type

Clay

Soil pH

7.1-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (117 days to spare)
Start indoors: Jan 24 Transplant: Feb 28 🍅 Harvest: May 23 – Jul 18
Recommended (50%) ✓ Fits season (115 days to spare)
Start indoors: Feb 5 Transplant: Mar 12 🍅 Harvest: Jun 4 – Jul 30
Safe Start (90%) ✓ Fits season (103 days to spare)
Start indoors: Mar 9 Transplant: Apr 13 🍅 Harvest: Jul 6 – Aug 31

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 Williamson County

How your county's soil matches Squash (Winter)'s growing requirements.

Soil pH

Your soil pH (7.1–7.8) is more alkaline than Squash (Winter) prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Heavy clay soil (46% clay) in Williamson County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.

Drainage

Drainage is adequate for Squash (Winter).

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Squash (Winter).

How to Plant Squash (Winter)

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

Succession Planting Squash (Winter)

3
successive plantings in your 262-day season

Sow every 9.1 weeks. Last sowing by Jul 25 to harvest before frost.

Plant Water Budget

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

Monthly Watering Guide for Squash (Winter)

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

Month Squash (Winter) Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 2" 0" ❄️ Dormant
Mar 4.3" 3.4" 0.9" 💧 Light watering
Apr 4.3" 6.5" 0" ✅ Rainfall sufficient
May 4.3" 7.7" 0" ✅ Rainfall sufficient
Jun 4.3" 7.6" 0" ✅ Rainfall sufficient
Jul 4.3" 6.6" 0" ✅ Rainfall sufficient
Aug 4.3" 6.1" 0" ✅ Rainfall sufficient
Sep 4.3" 5.4" 0" ✅ Rainfall sufficient
Oct 4.3" 3.7" 0.6" 💧 Light watering
Nov 4.3" 1.7" 2.6" 🚿 Regular watering
Dec 1.3" 0" ❄️ Dormant

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

Squash (Winter) 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.

Squash (Winter) needs ~2,050 GDD — county provides 5,371 GDD Excellent fit

Squash (Winter) Planting Timeline — Williamson County, TX

Squash (Winter) Planting Calendar

Activity When Date Range
Start Indoors February 5 Feb 5 – Feb 19
Transplant Outdoors March 12 Mar 12 – Mar 26
Direct Sow March 5 Mar 5 – Mar 26
Harvest June 4 Jun 4 – Jul 30

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

Month-by-Month Timeline

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

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 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9a

📆 Growing Season

262 days in Williamson County

Growing Tips for Squash (Winter) in Williamson County

Direct sow Squash (Winter) outdoors after March 05 in Williamson County when soil has warmed and frost danger has passed.

With Williamson County's clay soil (46% clay), work in 3-4 inches of compost before planting Squash (Winter). Avoid tilling when soil is wet to prevent compaction.

Common pests for Squash (Winter) in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow after last frost on rich mounds. Allow ample space for sprawling vines. Cure harvested fruits in the sun for 10 days before storing in a cool, dry place.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Squash (Winter) in Williamson County, TX?

Williamson County is in Zone 9a with an average last frost of March 5. Plan your Squash (Winter) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Williamson County, TX?

Williamson County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is March 5 and first fall frost is November 22.

🌱

Your Williamson County Garden Planner — Free

A 24-page printable planner built for Williamson County (Zone 9a). 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 Williamson County, TX. Local conditions may vary. Last updated: May 2026.

Sources & credits

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