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When to Plant Cauliflower in St. Tammany Parish, LA

St. Tammany Parish, Louisiana Zone 9a May

Your May planting checklist for St. Tammany Parish, Louisiana

Your St. Tammany Parish, Louisiana garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost February 20
Avg. first frost November 23
Soil temp (4") 74°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Bring in the cauliflower

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

To set up a strong June, finish these tasks
  • First harvests: cauliflower

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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.

St. Tammany Parish, Louisiana is in USDA Zone 9a. The average last spring frost is February 20 and the first fall frost is November 23, giving you a growing season of approximately 276 days.

At an elevation of 321 feet, St. Tammany Parish receives approximately 57.9 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°F, so Cauliflower may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — 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.

St. Tammany Parish, LA (Zone 9a) Year-round
276 days
Last Spring Frost February 20
276 growing days
First Fall Frost November 23

St. Tammany Parish Soil Profile

Soil Type

Sandy Loam

Soil pH

4.8-6.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (170 days to spare)
Start indoors: Jan 2 Transplant: Jan 30 🍅 Harvest: Mar 27 – May 29
Recommended (50%) ✓ Fits season (157 days to spare)
Start indoors: Jan 23 Transplant: Feb 20 🍅 Harvest: Apr 17 – Jun 19
Safe Start (90%) ✓ Fits season (144 days to spare)
Start indoors: Mar 2 Transplant: Mar 30 🍅 Harvest: May 25 – Jul 27

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 St. Tammany Parish

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

Soil pH

Your soil pH (4.8–6.1) is more acidic than Cauliflower prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Cauliflower.

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 276-day season

Sow every 6.3 weeks. Last sowing by Aug 15 to harvest before frost.

For a dedicated fall crop, sow by Sep 28.

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 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 4.5" 0" ❄️ Dormant
Feb 4.3" 4.5" 0" ✅ Rainfall sufficient
Mar 4.3" 5.8" 0" ✅ Rainfall sufficient
Apr 4.3" 4.2" 0.1" 💧 Light watering
May 4.3" 5.2" 0" ✅ Rainfall sufficient
Jun 4.3" 4.6" 0" ✅ Rainfall sufficient
Jul 4.3" 6.8" 0" ✅ Rainfall sufficient
Aug 4.3" 5.3" 0" ✅ Rainfall sufficient
Sep 4.3" 4.2" 0.1" 💧 Light watering
Oct 4.3" 4.1" 0.2" 💧 Light watering
Nov 4.3" 4.3" 0" ✅ Rainfall sufficient
Dec 4.3" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in St. Tammany Parish). Supplement amounts are based on average rainfall — 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" — 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.

Cauliflower needs ~1,705 GDD — county provides 6,094 GDD Excellent fit

Cauliflower Planting Timeline — St. Tammany Parish, LA

Cauliflower Planting Calendar

Activity When Date Range
Start Indoors January 23 Jan 23 – Feb 6
Transplant Outdoors February 20 Feb 20 – Mar 6
Direct Sow January 30 Jan 30 – Feb 20
Harvest April 17 Apr 17 – Jun 19
Fall Sowing September 28 Sep 28 – Oct 12

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

55–100 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

276 days in St. Tammany Parish

Growing Tips for Cauliflower in St. Tammany Parish

Direct sow Cauliflower outdoors after February 20 in St. Tammany Parish when soil has warmed and frost danger has passed.

Sandy soil in St. Tammany Parish dries quickly — mulch Cauliflower with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

Summer highs in St. Tammany Parish reach 96°F — 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 St. Tammany Parish, LA?

St. Tammany Parish is in Zone 9a with an average last frost of February 20. Plan your Cauliflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is St. Tammany Parish, LA?

St. Tammany Parish, Louisiana is in USDA Hardiness Zone 9a. The average last spring frost is February 20 and first fall frost is November 23.

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Your St. Tammany Parish Garden Planner — Free

A 24-page printable planner built for St. Tammany Parish (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 St. Tammany Parish, LA. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.