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When to Plant Cauliflower in Union County, FL

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.

Union County, Florida is in USDA Zone 9a. The average last spring frost is March 1 and the first fall frost is November 27, giving you a growing season of approximately 271 days.

At an elevation of 360 feet, Union County receives approximately 60.6 inches of rainfall annually with predominantly sand soil. Summer highs average 96ยฐF, 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.

Union County, FL (Zone 9a) Year-round
271 days
Last Spring Frost March 1
271 growing days
First Fall Frost November 27

Union County Soil Profile

Soil Type

Sand

Soil pH

5.2-6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (156 days to spare)
Start indoors: Jan 17 Transplant: Feb 14 🍅 Harvest: Apr 11 – Jun 13
Recommended (50%) ✓ Fits season (152 days to spare)
Start indoors: Feb 1 Transplant: Mar 1 🍅 Harvest: Apr 26 – Jun 28
Safe Start (90%) ✓ Fits season (150 days to spare)
Start indoors: Feb 26 Transplant: Mar 26 🍅 Harvest: May 21 – Jul 23

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 Union County

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

Soil pH

Your soil pH (5.2โ€“6.0) is more acidic than Cauliflower prefers (6.0โ€“7.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Cauliflower is a heavy drinker but your soil drains very quickly. Mulch heavily and consider drip irrigation.

Organic Matter

Organic matter is low (1.3%). Add 2-3 inches of compost before planting 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

5
successive plantings in your 271-day season

Sow every 6.3 weeks. Last sowing by Aug 19 to harvest before frost.

For a dedicated fall crop, sow by Oct 02.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 870 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€” 3.1" 0" โ„๏ธ Dormant
Feb โ€” 2.7" 0" โ„๏ธ Dormant
Mar 4.3" 3.5" 0.8" ๐Ÿ’ง Light watering
Apr 4.3" 2.8" 1.5" ๐Ÿ’ง Light watering
May 4.3" 4.4" 0" โœ… Rainfall sufficient
Jun 4.3" 8.1" 0" โœ… Rainfall sufficient
Jul 4.3" 10" 0" โœ… Rainfall sufficient
Aug 4.3" 9" 0" โœ… Rainfall sufficient
Sep 4.3" 7.2" 0" โœ… Rainfall sufficient
Oct 4.3" 4.5" 0" โœ… Rainfall sufficient
Nov 4.3" 2.7" 1.6" ๐Ÿ’ง Light watering
Dec โ€” 2.5" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Union 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 ~1,705 GDD — county provides 5,962 GDD Excellent fit

Cauliflower Planting Timeline โ€” Union County, FL

Cauliflower Planting Calendar

Activity When Date Range
Start Indoors February 1 Feb 1 โ€“ Feb 15
Transplant Outdoors March 1 Mar 1 โ€“ Mar 15
Direct Sow February 8 Feb 8 โ€“ Mar 1
Harvest April 26 Apr 26 โ€“ Jun 28
Fall Sowing October 2 Oct 2 โ€“ Oct 16

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors Direct Sow
March Transplant Outdoors Direct Sow
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 1-2 times/week

๐Ÿ“… Days to Maturity

55โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

271 days in Union County

Growing Tips for Cauliflower in Union County

Direct sow Cauliflower outdoors after March 01 in Union County when soil has warmed and frost danger has passed.

Sandy soil in Union 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 Union County reach 96ยฐF 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 Union County, FL?

Union County is in Zone 9a with an average last frost of March 1. Plan your Cauliflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Union County, FL?

Union County, Florida is in USDA Hardiness Zone 9a. The average last spring frost is March 1 and first fall frost is November 27.

๐ŸŒฑ

Plan Your Garden with Confidence

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