When to Plant Basil in St. Tammany Parish, LA
May to-do list for St. Tammany Parish, Louisiana
Here's what deserves your attention in St. Tammany Parish, Louisiana this month. Everything below is tailored to Zone 9a and timed around your local frost dates.
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Basket week: basil
This is the payoff month. Bring a basket, bring a friend, and get into the beds.
Coming up in June — start thinking about
- First harvests: basil
Basil is a fragrant warm-season herb essential to Italian and Thai cuisines. It comes in many varieties including sweet, Thai, purple, and lemon types.
St. Tammany Parish, Louisiana is in USDA Zone 9a. The average last spring frost is February 20 and the first fall frost is November 23, giving you a growing season of approximately 276 days.
At an elevation of 321 feet, St. Tammany Parish receives approximately 57.9 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°F, so Basil may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Basil will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Basil root diseases.
St. Tammany Parish Soil Profile
Soil Type
Sandy Loam
Soil pH
4.8-6.1
Drainage
Well Drained
Plant Planting Risk Windows
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. Tammany Parish
How your county's soil matches Basil's growing requirements.
Soil pH
Your soil pH (4.8–6.1) is more acidic than Basil prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
Sandy soil in St. Tammany Parish warms quickly in spring but drains fast. Basil will need more frequent watering and regular compost additions to retain nutrients.
Drainage
Drainage is adequate for Basil.
Organic Matter
Organic matter is moderate (2.1%). Annual compost additions will help Basil.
How to Plant Basil
Succession Planting Basil
Sow every 5.7 weeks. Last sowing by Sep 09 to harvest before frost.
Plant Water Budget
Monthly Watering Guide for Basil
Basil needs approximately 0.6 inches of water per week (2.6" per month). Here's how your county's rainfall compares month by month.
| Month | Basil Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 4.5" | 0" | ❄️ Dormant |
| Feb | 2.6" | 4.5" | 0" | ✅ Rainfall sufficient |
| Mar | 2.6" | 5.8" | 0" | ✅ Rainfall sufficient |
| Apr | 2.6" | 4.2" | 0" | ✅ Rainfall sufficient |
| May | 2.6" | 5.2" | 0" | ✅ Rainfall sufficient |
| Jun | 2.6" | 4.6" | 0" | ✅ Rainfall sufficient |
| Jul | 2.6" | 6.8" | 0" | ✅ Rainfall sufficient |
| Aug | 2.6" | 5.3" | 0" | ✅ Rainfall sufficient |
| Sep | 2.6" | 4.2" | 0" | ✅ Rainfall sufficient |
| Oct | 2.6" | 4.1" | 0" | ✅ Rainfall sufficient |
| Nov | 2.6" | 4.3" | 0" | ✅ Rainfall sufficient |
| Dec | — | 4.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Feb–Nov in St. Tammany Parish). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Basil 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.
Basil Planting Timeline — St. Tammany Parish, LA
Basil Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 9 | Jan 9 – Jan 23 |
| Transplant Outdoors | February 27 | Feb 27 – Mar 13 |
| Direct Sow | February 27 | Feb 27 – Mar 20 |
| Harvest | April 24 | Apr 24 – Jun 26 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Transplant Outdoors Direct Sow |
| March | Transplant Outdoors Direct Sow |
| April | Harvest |
| May | Harvest |
| June | Harvest |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.6"/week · Natural rainfall sufficient
📅 Days to Maturity
50–75 days
🧪 Soil pH
Needs 6–7 · Your soil: too_acidic
🗺️ USDA Zone
Zone 9a
📆 Growing Season
276 days in St. Tammany Parish
Growing Tips for Basil in St. Tammany Parish
Direct sow Basil outdoors after February 20 in St. Tammany Parish when soil has warmed and frost danger has passed.
Sandy soil in St. Tammany Parish dries quickly — mulch Basil 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. Tammany Parish, provide afternoon shade for Basil and water deeply in the morning.
General growing tips
Start seeds indoors or direct sow after last frost. Pinch flower buds to extend leaf production. Harvest leaves from the top down, cutting just above a leaf pair.
Recommended Basil Varieties for St. Tammany Parish
Downy mildew-resistant basil for your humid climate
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Isolate 150 ft between varieties. Different basil species can cross.
Basil in Other Locations
Frequently Asked Questions
When should I plant Basil in St. Tammany Parish, LA?
St. Tammany Parish is in Zone 9a with an average last frost of February 20. Plan your Basil planting based on this frost date — see the calendar above for exact timing.
What planting zone is St. Tammany Parish, LA?
St. Tammany Parish, Louisiana is in USDA Hardiness Zone 9a. The average last spring frost is February 20 and first fall frost is November 23.
Your St. Tammany Parish Garden Planner — Free
A 24-page printable planner built for St. Tammany 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.