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When to Plant Celeriac in St. James Parish, LA

St. James Parish, Louisiana Zone 9a May

Top priorities for St. James Parish, Louisiana gardeners in May

We've pulled the most time-sensitive tasks for St. James Parish, Louisiana this May and put them front and centre. Tackle them in order.

Avg. last frost February 13
Avg. first frost December 6
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Harvest celeriac as they ripen

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

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

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Celeriac is a celery relative grown for its knobby, flavorful root rather than its stalks. It has a rich celery flavor and is excellent roasted, mashed, or in soups.

St. James Parish, Louisiana is in USDA Zone 9a. The average last spring frost is February 13 and the first fall frost is December 6, giving you a growing season of approximately 296 days.

At an elevation of 471 feet, St. James Parish receives approximately 52 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 97°F, so Celeriac may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Celeriac will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Celeriac root diseases.

St. James Parish, LA (Zone 9a) Year-round
296 days
Last Spring Frost February 13
296 growing days
First Fall Frost December 6

St. James Parish Soil Profile

Soil Type

Sandy Loam

Soil pH

5-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (166 days to spare)
Start indoors: Dec 28 Transplant: Jan 25 🍅 Harvest: May 10 – Jun 14
Recommended (50%) ✓ Fits season (156 days to spare)
Start indoors: Jan 16 Transplant: Feb 13 🍅 Harvest: May 29 – Jul 3
Safe Start (90%) ✓ Fits season (146 days to spare)
Start indoors: Feb 9 Transplant: Mar 9 🍅 Harvest: Jun 22 – 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. James Parish

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

Soil pH

Your soil pH (5.0–6.2) is more acidic than Celeriac prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is low (2.0%). Add 2-3 inches of compost before planting Celeriac.

How to Plant Celeriac

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

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

Plant Water Budget

Plant needs
0.9″/week
Rainfall provides
0.7″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 435 gal / 100 sq ft

Monthly Watering Guide for Celeriac

Celeriac needs approximately 0.9 inches of water per week (3.9" per month). Here's how your county's rainfall compares month by month.

Month Celeriac Needs Rainfall You Supplement Action
Jan 4.2" 0" ❄️ Dormant
Feb 3.9" 4.4" 0" ✅ Rainfall sufficient
Mar 3.9" 4.9" 0" ✅ Rainfall sufficient
Apr 3.9" 3.4" 0.5" 💧 Light watering
May 3.9" 4.6" 0" ✅ Rainfall sufficient
Jun 3.9" 4.9" 0" ✅ Rainfall sufficient
Jul 3.9" 5.4" 0" ✅ Rainfall sufficient
Aug 3.9" 5.4" 0" ✅ Rainfall sufficient
Sep 3.9" 3.9" 0" ✅ Rainfall sufficient
Oct 3.9" 2.9" 1" 💧 Light watering
Nov 3.9" 4.2" 0" ✅ Rainfall sufficient
Dec 3.9" 3.8" 0.1" 💧 Light watering

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

Celeriac 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.

Celeriac needs ~2,502 GDD — county provides 6,756 GDD Excellent fit

Celeriac Planting Timeline — St. James Parish, LA

Celeriac Planting Calendar

Activity When Date Range
Start Indoors January 16 Jan 16 – Jan 30
Transplant Outdoors February 13 Feb 13 – Feb 27
Direct Sow January 23 Jan 23 – Feb 13
Harvest May 29 May 29 – Jul 3
Fall Sowing October 11 Oct 11 – Oct 25

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.9"/week · Only during dry spells

📅 Days to Maturity

100–120 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

296 days in St. James Parish

Growing Tips for Celeriac in St. James Parish

Direct sow Celeriac outdoors after February 13 in St. James Parish when soil has warmed and frost danger has passed.

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

With summer highs reaching 97°F in St. James Parish, provide afternoon shade for Celeriac and water deeply in the morning.

Common pests for Celeriac in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 10-12 weeks before last frost. Remove side roots as they develop to encourage a single large bulb. Harvest after a light frost for best flavor.

Companion Planting

Good Companions

Avoid Planting Near

  • Carrots
  • Parsnip

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Celeriac in St. James Parish, LA?

St. James Parish is in Zone 9a with an average last frost of February 13. Plan your Celeriac planting based on this frost date — see the calendar above for exact timing.

What planting zone is St. James Parish, LA?

St. James Parish, Louisiana is in USDA Hardiness Zone 9a. The average last spring frost is February 13 and first fall frost is December 6.

🌱

Your St. James Parish Garden Planner — Free

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

Sources & credits

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