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When to Plant Zucchini in Duval County, TX

Zucchini is an incredibly prolific summer squash that can produce an abundance of fruit from just a few plants. It is versatile in the kitchen from grilling to baking.

Duval County, Texas is in USDA Zone 9a. The average last spring frost is February 13 and the first fall frost is December 9, giving you a growing season of approximately 299 days.

At an elevation of 4,259 feet, Duval County receives approximately 55.2 inches of rainfall annually with predominantly loam soil. Summer highs average 102ยฐF, so Zucchini may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Zucchini root diseases.

Duval County, TX (Zone 9a) Year-round
299 days
Last Spring Frost February 13
299 growing days
First Fall Frost December 9

Duval County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (202 days to spare)
Start indoors: Dec 23 Transplant: Jan 27 🍅 Harvest: Mar 17 – May 12
Recommended (50%) ✓ Fits season (187 days to spare)
Start indoors: Jan 16 Transplant: Feb 20 🍅 Harvest: Apr 10 – Jun 5
Safe Start (90%) ✓ Fits season (175 days to spare)
Start indoors: Feb 8 Transplant: Mar 15 🍅 Harvest: May 3 – Jun 28

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 Duval County

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

Soil pH

Your soil pH (6.8โ€“7.3) is within Zucchini's preferred range (6.0โ€“7.5).

Soil Texture

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

Organic Matter

Organic matter is moderate (2.1%). Annual compost additions will help Zucchini.

How to Plant Zucchini

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

Succession Planting Zucchini

8
successive plantings in your 299-day season

Sow every 5.1 weeks. Last sowing by Oct 10 to harvest before frost.

Plant Water Budget

Plant needs
1.2″/week
Rainfall provides
0.8″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 1,141 gal / 100 sq ft

Monthly Watering Guide for Zucchini

Zucchini needs approximately 1.2 inches of water per week (5.2" per month). Here's how your county's rainfall compares month by month.

Month Zucchini Needs Rainfall You Supplement Action
Jan โ€” 1.6" 0" โ„๏ธ Dormant
Feb 5.2" 1.7" 3.5" ๐Ÿšฟ Regular watering
Mar 5.2" 4" 1.2" ๐Ÿ’ง Light watering
Apr 5.2" 5.3" 0" โœ… Rainfall sufficient
May 5.2" 8.7" 0" โœ… Rainfall sufficient
Jun 5.2" 8.4" 0" โœ… Rainfall sufficient
Jul 5.2" 6.8" 0" โœ… Rainfall sufficient
Aug 5.2" 6" 0" โœ… Rainfall sufficient
Sep 5.2" 5.7" 0" โœ… Rainfall sufficient
Oct 5.2" 3.6" 1.6" ๐Ÿ’ง Light watering
Nov 5.2" 1.9" 3.3" ๐Ÿšฟ Regular watering
Dec 5.2" 1.6" 3.6" ๐Ÿšฟ Regular watering

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

Zucchini 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.

Zucchini needs ~1,391 GDD — county provides 7,950 GDD Excellent fit

Zucchini Planting Timeline โ€” Duval County, TX

Zucchini Planting Calendar

Activity When Date Range
Start Indoors January 16 Jan 16 โ€“ Jan 30
Transplant Outdoors February 20 Feb 20 โ€“ Mar 6
Direct Sow February 13 Feb 13 โ€“ Mar 6
Harvest April 10 Apr 10 โ€“ Jun 5

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.2"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

45โ€“60 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

299 days in Duval County

Growing Tips for Zucchini in Duval County

Direct sow Zucchini outdoors after February 13 in Duval County when soil has warmed and frost danger has passed.

With summer highs reaching 102ยฐF in Duval County, provide afternoon shade for Zucchini and water deeply in the morning.

Your generous 300.0-day season in Duval County allows multiple plantings of Zucchini. Sow every 22.0 days for continuous harvest.

Common pests for Zucchini 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. Harvest when fruits are 6-8 inches long for best flavor and texture. Check plants daily in summer as fruits can double in size overnight.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Zucchini in Duval County, TX?

Duval County is in Zone 9a with an average last frost of February 13. Plan your Zucchini planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Duval County, TX?

Duval County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 13 and first fall frost is December 9.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Duval County gardeners in Zone 9a organize planting dates, track what's growing, and never miss a planting window.

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