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When to Plant Tomatoes in St. Bernard Parish, LA

St. Bernard Parish, Louisiana Zone 9b May

What to do in May

A quick May briefing for St. Bernard Parish, Louisiana gardeners — what's urgent, what's next, and what can wait.

Avg. last frost February 2
Avg. first frost December 11
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Bring in the tomatoes

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

June will be here before you know it — start on
  • First harvests: tomatoes

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Tomatoes are the most popular home garden crop, available in thousands of varieties from tiny cherries to massive beefsteaks. They are warm-season plants needing full sun.

St. Bernard Parish, Louisiana is in USDA Zone 9b. The average last spring frost is February 2 and the first fall frost is December 11, giving you a growing season of approximately 312 days.

At an elevation of 455 feet, St. Bernard Parish receives approximately 51.7 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 104°F, so Tomatoes may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Tomatoes will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Tomatoes root diseases.

St. Bernard Parish, LA (Zone 9b) Year-round
312 days
Last Spring Frost February 2
312 growing days
First Fall Frost December 11

St. Bernard Parish Soil Profile

Soil Type

Sandy Loam

Soil pH

5.2-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (178 days to spare)
Start indoors: Dec 11 Transplant: Jan 29 🍅 Harvest: Apr 2 – Jun 11
Recommended (50%) ✓ Fits season (172 days to spare)
Start indoors: Dec 22 Transplant: Feb 9 🍅 Harvest: Apr 13 – Jun 22
Safe Start (90%) ✓ Fits season (155 days to spare)
Start indoors: Jan 22 Transplant: Mar 12 🍅 Harvest: May 14 – 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 St. Bernard Parish

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

Soil pH

Your soil pH (5.2–6.5) is more acidic than Tomatoes prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Tomatoes.

Organic Matter

Organic matter is moderate (2.0%). Annual compost additions will help Tomatoes.

How to Plant Tomatoes

0.5"
Planting Depth
24"
Between Plants
36"
Between Rows

Succession Planting Tomatoes

6
successive plantings in your 312-day season

Sow every 6.9 weeks. Last sowing by Sep 17 to harvest before frost.

Plant Water Budget

Plant needs
1.2″/week
Rainfall provides
0.7″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 407 gal / 100 sq ft

Monthly Watering Guide for Tomatoes

Tomatoes 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 Tomatoes Needs Rainfall You Supplement Action
Jan 4.6" 0" ❄️ Dormant
Feb 5.2" 4.4" 0.8" 💧 Light watering
Mar 5.2" 5.3" 0" ✅ Rainfall sufficient
Apr 5.2" 4" 1.2" 💧 Light watering
May 5.2" 4.4" 0.8" 💧 Light watering
Jun 5.2" 4.8" 0.4" 💧 Light watering
Jul 5.2" 5.9" 0" ✅ Rainfall sufficient
Aug 5.2" 4.2" 1" 💧 Light watering
Sep 5.2" 3.6" 1.6" 💧 Light watering
Oct 5.2" 3.1" 2.1" 💧 Light watering
Nov 5.2" 3.9" 1.3" 💧 Light watering
Dec 5.2" 3.5" 1.7" 💧 Light watering

Water needs are for active growing months only (Feb–Dec in St. Bernard Parish). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Tomatoes 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.

Tomatoes needs ~2,030 GDD — county provides 8,764 GDD Excellent fit

Tomatoes Planting Timeline — St. Bernard Parish, LA

Tomatoes Planting Calendar

Activity When Date Range
Start Indoors December 22 Dec 22 – Jan 5
Transplant Outdoors February 9 Feb 9 – Feb 23
Direct Sow February 2 Feb 2 – Feb 23
Harvest April 13 Apr 13 – Jun 22

Plant 0.5" deep · 24" apart · Rows 36" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.2"/week · Only during dry spells

📅 Days to Maturity

60–85 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9b

📆 Growing Season

312 days in St. Bernard Parish

Growing Tips for Tomatoes in St. Bernard Parish

Direct sow Tomatoes outdoors after February 02 in St. Bernard Parish when soil has warmed and frost danger has passed.

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

With summer highs reaching 104°F in St. Bernard Parish, provide afternoon shade for Tomatoes and water deeply in the morning.

Common pests for Tomatoes in this region include tomato hornworm and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 6-8 weeks before last frost. Bury transplants deep to encourage rooting along the stem. Provide consistent moisture to prevent blossom end rot and cracking.

Recommended Tomatoes Varieties for St. Bernard Parish

Heat-set varieties that pollinate reliably above 90°F

Solar Fire Florida 91 Phoenix Heat Wave II

Your long season supports large indeterminate heirloom types

Brandywine (80d) Cherokee Purple (80d) San Marzano (80d) Mortgage Lifter (85d)

Disease-resistant varieties for your humid climate

Mountain Merit (VF) Defiant (LB) Iron Lady (EB/LB/SF)

Companion Planting

Good Companions

Avoid Planting Near

  • Cabbage
  • Fennel
  • Potatoes

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Tomatoes Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Scoop seeds from ripe fruit; ferment 2-3 days to remove gel coating.
Storage Store airtight; viable 4-6 years at 35°F, under 45% humidity.

Isolate 25 ft between varieties for purity. Use open-pollinated varieties for true-to-type seeds.

Frequently Asked Questions

When should I plant Tomatoes in St. Bernard Parish, LA?

St. Bernard Parish is in Zone 9b with an average last frost of February 2. Plan your Tomatoes planting based on this frost date — see the calendar above for exact timing.

What planting zone is St. Bernard Parish, LA?

St. Bernard Parish, Louisiana is in USDA Hardiness Zone 9b. The average last spring frost is February 2 and first fall frost is December 11.

🌱

Your St. Bernard Parish Garden Planner — Free

A 24-page printable planner built for St. Bernard Parish (Zone 9b). 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. Bernard 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.