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When to Plant Crosne in St. Mary Parish, LA

St. Mary Parish, Louisiana Zone 9b May

Your May game plan for St. Mary Parish, Louisiana

Your St. Mary 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 14
Avg. first frost December 5
Soil temp (4") 77°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
Get ahead of June
  • First harvests: crosne

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Crosne (Chinese artichoke) produces small, segmented white tubers with a crunchy texture and mild artichoke-nutty flavor. They are a rare delicacy in French cuisine.

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 Crosne may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Crosne 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 (78 days to spare)
Transplant: Feb 5 🍅 Harvest: Jul 9 – Sep 10
Recommended (50%) ✓ Fits season (77 days to spare)
Transplant: Feb 14 🍅 Harvest: Jul 18 – Sep 19
Safe Start (90%) ✓ Fits season (67 days to spare)
Transplant: Mar 11 🍅 Harvest: Aug 12 – Oct 14

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 Crosne's growing requirements.

Soil pH

Your soil pH (4.8–6.4) is more acidic than Crosne 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. Crosne will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Crosne.

Organic Matter

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

How to Plant Crosne

0.5"
Planting Depth
6"
Between Plants
12"
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 Crosne

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

Month Crosne 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.

Crosne 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.

Crosne needs ~3,719 GDD — county provides 6,268 GDD Excellent fit

Crosne Planting Timeline — St. Mary Parish, LA

Crosne Planting Calendar

Activity When Date Range
Direct Sow January 24 Jan 24 – Feb 14
Harvest June 27 Jun 27 – Aug 29
Fall Sowing October 10 Oct 10 – Oct 24

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

150–200 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 Crosne in St. Mary Parish

Direct sow Crosne 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 Crosne with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

General growing tips

Plant tubers 3 inches deep in spring. Mark the location well as plants die back. Harvest in late fall after frost. Leave some tubers in ground for next year. Very labor-intensive to harvest.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

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

St. Mary Parish is in Zone 9b with an average last frost of February 14. Plan your Crosne 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.