Blog

When to Plant Cauliflower in Galveston County, TX

Cauliflower is a cool-season brassica that produces dense white, purple, or green heads called curds. It is more finicky than broccoli but rewards with a mild, nutty flavor.

Galveston County, Texas is in USDA Zone 9a. The average last spring frost is February 5 and the first fall frost is December 7, giving you a growing season of approximately 305 days.

At an elevation of 9 feet, Galveston County receives approximately 72.5 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 100ยฐF, so Cauliflower may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Cauliflower will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Cauliflower root diseases.

Galveston County, TX (Zone 9a) Year-round
305 days
Last Spring Frost February 5
305 growing days
First Fall Frost December 7

Galveston County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.7-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (198 days to spare)
Start indoors: Dec 21 Transplant: Jan 18 🍅 Harvest: Mar 15 – May 17
Recommended (50%) ✓ Fits season (186 days to spare)
Start indoors: Jan 8 Transplant: Feb 5 🍅 Harvest: Apr 2 – Jun 4
Safe Start (90%) ✓ Fits season (173 days to spare)
Start indoors: Feb 6 Transplant: Mar 6 🍅 Harvest: May 1 – Jul 3

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 Galveston County

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

Soil pH

Your soil pH (5.7โ€“6.5) overlaps with Cauliflower's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

Sandy soil in Galveston County warms quickly in spring but drains fast. Cauliflower will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

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

How to Plant Cauliflower

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Cauliflower

6
successive plantings in your 305-day season

Sow every 6.3 weeks. Last sowing by Aug 29 to harvest before frost.

For a dedicated fall crop, sow by Oct 12.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Only during dry spells
Season total 13 gal / 100 sq ft

Monthly Watering Guide for Cauliflower

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

Month Cauliflower Needs Rainfall You Supplement Action
Jan โ€” 2.1" 0" โ„๏ธ Dormant
Feb 4.3" 2.2" 2.1" ๐Ÿ’ง Light watering
Mar 4.3" 5.4" 0" โœ… Rainfall sufficient
Apr 4.3" 8.2" 0" โœ… Rainfall sufficient
May 4.3" 10.4" 0" โœ… Rainfall sufficient
Jun 4.3" 10.9" 0" โœ… Rainfall sufficient
Jul 4.3" 8.7" 0" โœ… Rainfall sufficient
Aug 4.3" 8.6" 0" โœ… Rainfall sufficient
Sep 4.3" 6.2" 0" โœ… Rainfall sufficient
Oct 4.3" 5.2" 0" โœ… Rainfall sufficient
Nov 4.3" 2.6" 1.7" ๐Ÿ’ง Light watering
Dec 4.3" 1.9" 2.4" ๐Ÿšฟ Regular watering

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

Cauliflower 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.

Cauliflower needs ~1,938 GDD — county provides 7,650 GDD Excellent fit

Cauliflower Planting Timeline โ€” Galveston County, TX

Cauliflower Planting Calendar

Activity When Date Range
Start Indoors January 8 Jan 8 โ€“ Jan 22
Transplant Outdoors February 5 Feb 5 โ€“ Feb 19
Direct Sow January 15 Jan 15 โ€“ Feb 5
Harvest April 2 Apr 2 โ€“ Jun 4
Fall Sowing October 12 Oct 12 โ€“ Oct 26

Plant 1" deep ยท 15" apart ยท Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

55โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

305 days in Galveston County

Growing Tips for Cauliflower in Galveston County

Direct sow Cauliflower outdoors after February 05 in Galveston County when soil has warmed and frost danger has passed.

Sandy soil in Galveston County dries quickly โ€” mulch Cauliflower with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

Summer highs in Galveston County reach 100ยฐF โ€” grow Cauliflower as a spring or fall crop. Use shade cloth if planting in summer.

Common pests for Cauliflower in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 6 weeks before transplanting. Blanch white varieties by tying outer leaves over the head. Provide consistent moisture and avoid temperature extremes.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cauliflower in Galveston County, TX?

Galveston County is in Zone 9a with an average last frost of February 5. Plan your Cauliflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Galveston County, TX?

Galveston County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 5 and first fall frost is December 7.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Galveston 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 Galveston County, TX. Local conditions may vary. Last updated: April 2026.