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When to plant Onion in Tangipahoa Parish County,

In Zone 9a (Tangipahoa Parish County), direct-sow Onion between February 11 and March 4 for spring, after the March 4 last-frost mark. A second sowing from September 28 to October 12 extends the harvest into fall.

When to Plant Onion in Tangipahoa Parish, LA

Tangipahoa Parish, Louisiana Zone 9a June

Your June planting checklist for Tangipahoa Parish, Louisiana

A quick June briefing for Tangipahoa Parish, Louisiana gardeners — what's urgent, what's next, and what can wait.

Avg. last frost March 4
Avg. first frost November 23
Soil temp (4") 83°F
Watering Low
Pest pressure High
Daylight 14 hrs
  1. Harvest onion as they ripen

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

July will be here before you know it — start on
  • First harvests: onion

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Onions are a fundamental kitchen staple available in yellow, white, and red varieties. Choose long-day, short-day, or intermediate types based on your latitude.

Tangipahoa Parish, Louisiana is in USDA Zone 9a. The average last spring frost is March 4 and the first fall frost is November 23, giving you a growing season of approximately 264 days.

At an elevation of 111 feet, Tangipahoa Parish receives approximately 56.7 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 94°F, providing good warmth for Onion during the growing season. Sandy soil warms quickly in spring — great for early planting — but Onion will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Onion root diseases.

Tangipahoa Parish, LA (Zone 9a) Long season
264 days
Last Spring Frost March 4
264 growing days
First Fall Frost November 23

Tangipahoa Parish Soil Profile

Soil Type

Sandy Loam

Soil pH

4.8-6

Drainage

Well Drained

Onion Planting Risk Windows

Early Start (70% safe) ✓ Fits season (131 days to spare)
Start indoors: Jan 21 Transplant: Feb 18 🍅 Harvest: May 20 – Jul 8
Recommended (50%) ✓ Fits season (124 days to spare)
Start indoors: Feb 4 Transplant: Mar 4 🍅 Harvest: Jun 3 – Jul 22
Safe Start (90%) ✓ Fits season (123 days to spare)
Start indoors: Feb 26 Transplant: Mar 26 🍅 Harvest: Jun 25 – Aug 13

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 Tangipahoa Parish

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

Soil pH

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

Soil Texture

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

Drainage

Drainage is adequate for Onion.

Organic Matter

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

How to Plant Onion

1"
Planting Depth
6"
Between Plants
12"
Between Rows

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

Onion 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 Onion

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

Month Onion Needs Rainfall You Supplement Action
Jan 3.9" 0" ❄️ Dormant
Feb 4.9" 0" ❄️ Dormant
Mar 4.3" 4.7" 0" ✅ Rainfall sufficient
Apr 4.3" 4.7" 0" ✅ Rainfall sufficient
May 4.3" 5" 0" ✅ Rainfall sufficient
Jun 4.3" 4.8" 0" ✅ Rainfall sufficient
Jul 4.3" 6.2" 0" ✅ Rainfall sufficient
Aug 4.3" 5.8" 0" ✅ Rainfall sufficient
Sep 4.3" 4.3" 0" ✅ Rainfall sufficient
Oct 4.3" 3.9" 0.4" 💧 Light watering
Nov 4.3" 4" 0.3" 💧 Light watering
Dec 4.5" 0" ❄️ Dormant

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

Onion 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.

Onion needs ~2,152 GDD — county provides 5,412 GDD Excellent fit

Onion Planting Timeline — Tangipahoa Parish, LA

Onion Planting Calendar

Activity When Date Range
Start Indoors February 4 Feb 4 – Feb 18
Transplant Outdoors March 4 Mar 4 – Mar 18
Direct Sow February 11 Feb 11 – Mar 4
Harvest June 3 Jun 3 – Jul 22
Fall Sowing September 28 Sep 28 – Oct 12

Plant 1" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors Direct Sow
March Transplant Outdoors Direct Sow
April
May
June Harvest
July Harvest
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

90–120 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

264 days in Tangipahoa Parish

Growing Tips for Onion in Tangipahoa Parish

Direct sow Onion outdoors after March 04 in Tangipahoa Parish when soil has warmed and frost danger has passed.

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

Common pests for Onion in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 8-10 weeks before transplanting. Match day-length type to your latitude. Stop watering when tops begin to fall over and cure bulbs for 2-3 weeks before storage.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans
  • Asparagus

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Onion in Tangipahoa Parish, LA?

Tangipahoa Parish is in Zone 9a with an average last frost of March 4. Plan your Onion planting based on this frost date — see the calendar above for exact timing.

What planting zone is Tangipahoa Parish, LA?

Tangipahoa Parish, Louisiana is in USDA Hardiness Zone 9a. The average last spring frost is March 4 and first fall frost is November 23.

When should I plant Onion in Tangipahoa Parish County, ?

In Tangipahoa Parish County, , plant Onion after the last frost (around March 4) and before the first frost (around November 23). Best results when soil holds above 50°F.

What growing zone is Tangipahoa Parish County, for Onion?

Tangipahoa Parish County sits in USDA Zone 9a. Onion grows reliably in zones 3a through 10b, so it's a good fit here.

Can Onion grow in Tangipahoa Parish County's climate?

Yes — Onion grows well in Tangipahoa Parish County's temperate climate. Tangipahoa Parish County averages a 264-day frost-free season, with last frost around March 4 and first frost around November 23.

🌱

Your Tangipahoa Parish Garden Planner — Free

A 22-page printable planner built for Tangipahoa 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 Tangipahoa Parish, LA. Local conditions may vary. Last updated: June 2026.

Sources & credits

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