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When to Plant Sunflower in Goliad County, TX

Sunflowers are tall, cheerful annuals grown for their edible seeds and as pollinator magnets. They come in sizes from 2-foot dwarfs to 12-foot giants.

Goliad County, Texas is in USDA Zone 9a. The average last spring frost is February 24 and the first fall frost is December 4, giving you a growing season of approximately 283 days.

At an elevation of 3,928 feet, Goliad County receives approximately 62.6 inches of rainfall annually with predominantly loam soil. Summer highs average 95ยฐF, so Sunflower may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sunflower root diseases.

Goliad County, TX (Zone 9a) Year-round
283 days
Last Spring Frost February 24
283 growing days
First Fall Frost December 4

Goliad County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (158 days to spare)
Start indoors: Jan 1 Transplant: Feb 19 🍅 Harvest: Apr 30 – Jun 18
Recommended (50%) ✓ Fits season (157 days to spare)
Start indoors: Jan 13 Transplant: Mar 3 🍅 Harvest: May 12 – Jun 30
Safe Start (90%) ✓ Fits season (157 days to spare)
Start indoors: Jan 30 Transplant: Mar 20 🍅 Harvest: May 29 – Jul 17

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 Goliad County

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

Soil pH

Your soil pH (6.3โ€“7.3) is within Sunflower's preferred range (6.0โ€“7.5).

Soil Texture

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

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Sunflower.

How to Plant Sunflower

1"
Planting Depth
18"
Between Plants
30"
Between Rows

Succession Planting Sunflower

4
successive plantings in your 283-day season

Sow every 8 weeks. Last sowing by Aug 26 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.9″/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 Sunflower

Sunflower needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Sunflower Needs Rainfall You Supplement Action
Jan โ€” 1.4" 0" โ„๏ธ Dormant
Feb 2.2" 2.2" 0" โœ… Rainfall sufficient
Mar 2.2" 3.5" 0" โœ… Rainfall sufficient
Apr 2.2" 6.7" 0" โœ… Rainfall sufficient
May 2.2" 9.8" 0" โœ… Rainfall sufficient
Jun 2.2" 10.6" 0" โœ… Rainfall sufficient
Jul 2.2" 8.2" 0" โœ… Rainfall sufficient
Aug 2.2" 7.6" 0" โœ… Rainfall sufficient
Sep 2.2" 5.3" 0" โœ… Rainfall sufficient
Oct 2.2" 3.6" 0" โœ… Rainfall sufficient
Nov 2.2" 2.1" 0.1" ๐Ÿ’ง Light watering
Dec 2.2" 1.6" 0.6" ๐Ÿ’ง Light watering

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

Sunflower 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.

Sunflower needs ~1,806 GDD — county provides 6,035 GDD Excellent fit

Sunflower Planting Timeline โ€” Goliad County, TX

Sunflower Planting Calendar

Activity When Date Range
Start Indoors January 13 Jan 13 โ€“ Jan 27
Transplant Outdoors March 3 Mar 3 โ€“ Mar 17
Direct Sow February 24 Feb 24 โ€“ Mar 17
Harvest May 12 May 12 โ€“ Jun 30

Plant 1" deep ยท 18" apart ยท Rows 30" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Direct Sow
March Transplant Outdoors Direct Sow
April โ€”
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

0.5"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

70โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

283 days in Goliad County

Growing Tips for Sunflower in Goliad County

Direct sow Sunflower outdoors after February 24 in Goliad County when soil has warmed and frost danger has passed.

Common pests for Sunflower in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow after last frost. Stake tall varieties in windy areas. Harvest seed heads when the back turns brown and seeds are plump. Dry heads upside down.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sunflower in Goliad County, TX?

Goliad County is in Zone 9a with an average last frost of February 24. Plan your Sunflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Goliad County, TX?

Goliad County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 24 and first fall frost is December 4.

๐ŸŒฑ

Plan Your Garden with Confidence

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

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Goliad County, TX. Local conditions may vary. Last updated: April 2026.