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When to Plant Mustard Greens in St. Mary Parish, LA

Mustard greens are fast-growing brassicas with a spicy, peppery kick. They come in green, red, and purple varieties and are excellent cooked or in salads.

St. Mary Parish, Louisiana is in USDA Zone 9a. 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 95ยฐF, so Mustard Greens may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Mustard Greens will need more frequent watering and organic matter to retain nutrients.

St. Mary Parish, LA (Zone 9a) 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 (197 days to spare)
Start indoors: Jan 8 Transplant: Feb 5 🍅 Harvest: Mar 12 – May 14
Recommended (50%) ✓ Fits season (196 days to spare)
Start indoors: Jan 17 Transplant: Feb 14 🍅 Harvest: Mar 21 – May 23
Safe Start (90%) ✓ Fits season (186 days to spare)
Start indoors: Feb 11 Transplant: Mar 11 🍅 Harvest: Apr 15 – Jun 17

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.

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 โ€” consider drought-tolerant varieties and mulching

Mustard Greens needs ~850 GDD — county provides 6,268 GDD Excellent fit

Mustard Greens Planting Timeline โ€” St. Mary Parish, LA

Mustard Greens Planting Calendar

Activity When Date Range
Start Indoors January 17 Jan 17 โ€“ Jan 31
Transplant Outdoors February 14 Feb 14 โ€“ Feb 28
Direct Sow January 24 Jan 24 โ€“ Feb 14
Fall Sowing October 10 Oct 10 โ€“ Oct 24
Harvest March 21 Mar 21 โ€“ May 23

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate โ€” regular watering

Days to Maturity

30โ€“50 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 9a

Growing Season

294 days

Growing Tips for St. Mary Parish

Direct sow in early spring or fall. Harvest young leaves for milder flavor. Plants bolt quickly in heat so grow as a cool-season crop or provide shade.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Level Up Your Garden

Frequently Asked Questions

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

St. Mary Parish is in Zone 9a with an average last frost of February 14. Plan your Mustard Greens planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is St. Mary Parish, LA?

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

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help St. Mary Parish gardeners in Zone 9a organize planting dates, track what's growing, and never miss a planting window.

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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: April 2026.