Blog

When to Plant Mache in St. Helena Parish, LA

St. Helena Parish, Louisiana Zone 9a May

What to do in May

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

Avg. last frost March 5
Avg. first frost November 30
Soil temp (4") 71°F
Watering Moderate
Pest pressure High
Daylight 13.6 hrs
  1. Pick mache

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

Instant PDF download. No spam, unsubscribe any time.

Mache (corn salad) is a cold-hardy salad green with small, rounded, tender leaves and a mild, nutty flavor. It thrives in cool weather and even overwinters in many climates.

St. Helena Parish, Louisiana is in USDA Zone 9a. The average last spring frost is March 5 and the first fall frost is November 30, giving you a growing season of approximately 270 days.

At an elevation of 437 feet, St. Helena Parish receives approximately 50 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°F, so Mache may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Mache will need more frequent watering and organic matter to retain nutrients.

St. Helena Parish, LA (Zone 9a) Year-round
270 days
Last Spring Frost March 5
270 growing days
First Fall Frost November 30

St. Helena Parish Soil Profile

Soil Type

Sandy Loam

Soil pH

4.8-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (201 days to spare)
Start indoors: Jan 18 Transplant: Feb 15 🍅 Harvest: Mar 29 – May 3
Recommended (50%) ✓ Fits season (193 days to spare)
Start indoors: Feb 5 Transplant: Mar 5 🍅 Harvest: Apr 16 – May 21
Safe Start (90%) ✓ Fits season (187 days to spare)
Start indoors: Feb 26 Transplant: Mar 26 🍅 Harvest: May 7 – Jun 11

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. Helena Parish

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

Soil pH

Your soil pH (4.8–6.5) is more acidic than Mache prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is low (1.7%). Add 2-3 inches of compost before planting Mache.

How to Plant Mache

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

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

Succession Planting Mache

8
successive plantings in your 270-day season

Sow every 4.6 weeks. Last sowing by Oct 01 to harvest before frost.

For a dedicated fall crop, sow by Oct 05.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 534 gal / 100 sq ft

Monthly Watering Guide for Mache

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

Month Mache Needs Rainfall You Supplement Action
Jan 3.8" 0" ❄️ Dormant
Feb 3.7" 0" ❄️ Dormant
Mar 4.3" 5.5" 0" ✅ Rainfall sufficient
Apr 4.3" 3.3" 1" 💧 Light watering
May 4.3" 3.6" 0.7" 💧 Light watering
Jun 4.3" 4.9" 0" ✅ Rainfall sufficient
Jul 4.3" 4.7" 0" ✅ Rainfall sufficient
Aug 4.3" 5.1" 0" ✅ Rainfall sufficient
Sep 4.3" 3.6" 0.7" 💧 Light watering
Oct 4.3" 3.3" 1" 💧 Light watering
Nov 4.3" 4.4" 0" ✅ Rainfall sufficient
Dec 4" 0" ❄️ Dormant

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

Mache 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.

Mache needs ~1,100 GDD — county provides 5,940 GDD Excellent fit

Mache Planting Timeline — St. Helena Parish, LA

Mache Planting Calendar

Activity When Date Range
Start Indoors February 5 Feb 5 – Feb 19
Transplant Outdoors March 5 Mar 5 – Mar 19
Direct Sow February 12 Feb 12 – Mar 5
Harvest April 16 Apr 16 – May 21
Fall Sowing October 5 Oct 5 – Oct 19

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

270 days in St. Helena Parish

Growing Tips for Mache in St. Helena Parish

Direct sow Mache outdoors after March 05 in St. Helena Parish when soil has warmed and frost danger has passed.

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

With summer highs reaching 96°F in St. Helena Parish, provide afternoon shade for Mache and water deeply in the morning.

Your generous 270.0-day season in St. Helena Parish allows multiple plantings of Mache. Sow every 20.0 days for continuous harvest.

General growing tips

Direct sow in early spring or late summer for fall and winter harvest. Seeds need light to germinate so press gently into soil surface. Harvest whole rosettes.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Mache in St. Helena Parish, LA?

St. Helena Parish is in Zone 9a with an average last frost of March 5. Plan your Mache planting based on this frost date — see the calendar above for exact timing.

What planting zone is St. Helena Parish, LA?

St. Helena Parish, Louisiana is in USDA Hardiness Zone 9a. The average last spring frost is March 5 and first fall frost is November 30.

🌱

Your St. Helena Parish Garden Planner — Free

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

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for St. Helena 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.