Blog

When to Plant Mustard Greens in St. John the Baptist 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. John the Baptist Parish, Louisiana is in USDA Zone 9a. The average last spring frost is February 20 and the first fall frost is December 1, giving you a growing season of approximately 284 days.

At an elevation of 309 feet, St. John the Baptist Parish receives approximately 53.7 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 103°F, so Mustard Greens may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Mustard Greens will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Mustard Greens root diseases.

St. John the Baptist Parish, LA (Zone 9a) Year-round
284 days
Last Spring Frost February 20
284 growing days
First Fall Frost December 1

St. John the Baptist Parish Soil Profile

Soil Type

Sandy Loam

Soil pH

4.8-6.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (190 days to spare)
Start indoors: Jan 9 Transplant: Feb 6 🍅 Harvest: Mar 13 – May 15
Recommended (50%) ✓ Fits season (186 days to spare)
Start indoors: Jan 23 Transplant: Feb 20 🍅 Harvest: Mar 27 – May 29
Safe Start (90%) ✓ Fits season (173 days to spare)
Start indoors: Feb 22 Transplant: Mar 22 🍅 Harvest: Apr 26 – Jun 28

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
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

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

Mustard Greens needs ~1,090 GDD — county provides 7,766 GDD Excellent fit

Mustard Greens Planting Timeline — St. John the Baptist Parish, LA

Mustard Greens Planting Calendar

Activity When Date Range
Start Indoors January 23 Jan 23 – Feb 6
Transplant Outdoors February 20 Feb 20 – Mar 6
Direct Sow January 30 Jan 30 – Feb 20
Fall Sowing October 6 Oct 6 – Oct 20
Harvest March 27 Mar 27 – May 29

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate — regular watering

Days to Maturity

30–50 days

Soil pH

6 – 7

USDA Zone

Zone 9a

Growing Season

284 days

Growing Tips for St. John the Baptist 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. John the Baptist Parish, LA?

St. John the Baptist Parish is in Zone 9a with an average last frost of February 20. Plan your Mustard Greens planting based on this frost date — see the calendar above for exact timing.

What planting zone is St. John the Baptist Parish, LA?

St. John the Baptist Parish, Louisiana is in USDA Hardiness Zone 9a. The average last spring frost is February 20 and first fall frost is December 1.

🌱

Plan Your Garden with Confidence

Get our free Garden Planner — designed to help St. John the Baptist Parish gardeners in Zone 9a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for St. John the Baptist Parish, LA. Local conditions may vary. Last updated: April 2026.