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When to Plant Catnip in St. James Parish, LA

St. James Parish, Louisiana Zone 9a May

What to do in May

May is a pivotal month for St. James Parish, Louisiana gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost February 13
Avg. first frost December 6
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Bring in the catnip

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

June prep starts now
  • First harvests: catnip

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Catnip is a hardy perennial herb in the mint family known for its effect on cats. It also makes a calming tea and is a useful companion plant that repels some pests.

St. James Parish, Louisiana is in USDA Zone 9a. The average last spring frost is February 13 and the first fall frost is December 6, giving you a growing season of approximately 296 days.

At an elevation of 471 feet, St. James Parish receives approximately 52 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 97°F, so Catnip may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Catnip will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Catnip root diseases.

St. James Parish, LA (Zone 9a) Year-round
296 days
Last Spring Frost February 13
296 growing days
First Fall Frost December 6

St. James Parish Soil Profile

Soil Type

Sandy Loam

Soil pH

5-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (173 days to spare)
Transplant: Feb 1 🍅 Harvest: Apr 5 – Jun 7
Recommended (50%) ✓ Fits season (163 days to spare)
Transplant: Feb 20 🍅 Harvest: Apr 24 – Jun 26
Safe Start (90%) ✓ Fits season (153 days to spare)
Transplant: Mar 16 🍅 Harvest: May 18 – Jul 20

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. James Parish

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

Soil pH

Your soil pH (5.0–6.2) is more acidic than Catnip prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is low (2.0%). Add 2-3 inches of compost before planting Catnip.

How to Plant Catnip

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Catnip

5
successive plantings in your 296-day season

Sow every 6.9 weeks. Last sowing by Sep 17 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.7″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Catnip

Catnip needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Catnip Needs Rainfall You Supplement Action
Jan 4.2" 0" ❄️ Dormant
Feb 2.2" 4.4" 0" ✅ Rainfall sufficient
Mar 2.2" 4.9" 0" ✅ Rainfall sufficient
Apr 2.2" 3.4" 0" ✅ Rainfall sufficient
May 2.2" 4.6" 0" ✅ Rainfall sufficient
Jun 2.2" 4.9" 0" ✅ Rainfall sufficient
Jul 2.2" 5.4" 0" ✅ Rainfall sufficient
Aug 2.2" 5.4" 0" ✅ Rainfall sufficient
Sep 2.2" 3.9" 0" ✅ Rainfall sufficient
Oct 2.2" 2.9" 0" ✅ Rainfall sufficient
Nov 2.2" 4.2" 0" ✅ Rainfall sufficient
Dec 2.2" 3.8" 0" ✅ Rainfall sufficient

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

Catnip 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.

Catnip needs ~1,592 GDD — county provides 6,756 GDD Excellent fit

Catnip Planting Timeline — St. James Parish, LA

Catnip Planting Calendar

Activity When Date Range
Transplant Outdoors February 20 Feb 20 – Mar 6
Harvest April 24 Apr 24 – Jun 26

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February Transplant Outdoors
March Transplant Outdoors
April Harvest
May Harvest
June Harvest
July
August
September
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

60–80 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

296 days in St. James Parish

Growing Tips for Catnip in St. James Parish

Direct sow Catnip outdoors after February 13 in St. James Parish when soil has warmed and frost danger has passed.

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

With summer highs reaching 97°F in St. James Parish, provide afternoon shade for Catnip and water deeply in the morning.

General growing tips

Direct sow or start indoors. Catnip is very easy to grow and can become invasive. Harvest leaves before flowering for tea. Protect young plants from cats.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Catnip in St. James Parish, LA?

St. James Parish is in Zone 9a with an average last frost of February 13. Plan your Catnip planting based on this frost date — see the calendar above for exact timing.

What planting zone is St. James Parish, LA?

St. James Parish, Louisiana is in USDA Hardiness Zone 9a. The average last spring frost is February 13 and first fall frost is December 6.

🌱

Your St. James Parish Garden Planner — Free

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

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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. James 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.