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When to Plant Parsnip in St. Mary Parish, LA

St. Mary Parish, Louisiana Zone 9b May

Your May planting checklist for St. Mary Parish, Louisiana

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

Avg. last frost February 14
Avg. first frost December 5
Soil temp (4") 77°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. It's harvest week for parsnip

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

June prep starts now
  • First harvests: parsnip

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Parsnips are a sweet, nutty root vegetable that develops best flavor after exposure to frost. They require a long growing season but reward patient gardeners.

St. Mary Parish, Louisiana is in USDA Zone 9b. The average last spring frost is February 14 and the first fall frost is December 5, giving you a growing season of approximately 294 days.

At an elevation of 252 feet, St. Mary Parish receives approximately 48.5 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 95°F, so Parsnip may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Parsnip will need more frequent watering and organic matter to retain nutrients.

St. Mary Parish, LA (Zone 9b) Year-round
294 days
Last Spring Frost February 14
294 growing days
First Fall Frost December 5

St. Mary Parish Soil Profile

Soil Type

Sandy Loam

Soil pH

4.8-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (148 days to spare)
Transplant: Feb 5 🍅 Harvest: May 21 – Jul 2
Recommended (50%) ✓ Fits season (147 days to spare)
Transplant: Feb 14 🍅 Harvest: May 30 – Jul 11
Safe Start (90%) ✓ Fits season (137 days to spare)
Transplant: Mar 11 🍅 Harvest: Jun 24 – Aug 5

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. Mary Parish

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

Soil pH

Your soil pH (4.8–6.4) is more acidic than Parsnip prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Parsnip.

Organic Matter

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

How to Plant Parsnip

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
1.0″/week
Rainfall provides
0.7″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 30 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Parsnip

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

Month Parsnip Needs Rainfall You Supplement Action
Jan 3.6" 0" ❄️ Dormant
Feb 4.3" 3.4" 0.9" 💧 Light watering
Mar 4.3" 5.1" 0" ✅ Rainfall sufficient
Apr 4.3" 3.8" 0.5" 💧 Light watering
May 4.3" 3.8" 0.5" 💧 Light watering
Jun 4.3" 3.6" 0.7" 💧 Light watering
Jul 4.3" 5.6" 0" ✅ Rainfall sufficient
Aug 4.3" 5.1" 0" ✅ Rainfall sufficient
Sep 4.3" 3.5" 0.8" 💧 Light watering
Oct 4.3" 3.1" 1.2" 💧 Light watering
Nov 4.3" 3.9" 0.4" 💧 Light watering
Dec 4.3" 4.2" 0.1" 💧 Light watering

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

Parsnip 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.

Parsnip needs ~2,444 GDD — county provides 6,268 GDD Excellent fit

Parsnip Planting Timeline — St. Mary Parish, LA

Parsnip Planting Calendar

Activity When Date Range
Direct Sow January 24 Jan 24 – Feb 14
Harvest May 9 May 9 – Jun 20
Fall Sowing October 10 Oct 10 – Oct 24

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

100–130 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9b

📆 Growing Season

294 days in St. Mary Parish

Growing Tips for Parsnip in St. Mary Parish

Direct sow Parsnip outdoors after February 14 in St. Mary Parish when soil has warmed and frost danger has passed.

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

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

General growing tips

Use only fresh seed as parsnip seed viability declines rapidly. Sow directly in spring in deeply worked soil. Leave roots in the ground through winter for sweetest flavor.

Companion Planting

Good Companions

Avoid Planting Near

  • Carrots
  • Celery

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Parsnip in St. Mary Parish, LA?

St. Mary Parish is in Zone 9b with an average last frost of February 14. Plan your Parsnip planting based on this frost date — see the calendar above for exact timing.

What planting zone is St. Mary Parish, LA?

St. Mary Parish, Louisiana is in USDA Hardiness Zone 9b. The average last spring frost is February 14 and first fall frost is December 5.

🌱

Your St. Mary Parish Garden Planner — Free

A 24-page printable planner built for St. Mary 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. Mary 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.