When to Plant Leeks in St. Tammany Parish, LA
What to do in May
Each item below is timed to St. Tammany Parish, Louisiana's frost dates and soil temperatures. Skip nothing, stress about nothing.
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Harvest leeks as they ripen
Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.
Coming up in June — start thinking about
- First harvests: leeks
Leeks are a mild, sweet allium that produces long white shanks. They are more refined than onions and are a key ingredient in soups, stews, and gratins.
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 Leeks may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Leeks will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Leeks 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 Leeks's growing requirements.
Soil pH
Your soil pH (4.8–6.1) is more acidic than Leeks 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. Leeks will need more frequent watering and regular compost additions to retain nutrients.
Drainage
Drainage is adequate for Leeks.
Organic Matter
Organic matter is moderate (2.1%). Annual compost additions will help Leeks.
How to Plant Leeks
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Plant Water Budget
Monthly Watering Guide for Leeks
Leeks needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.
| Month | Leeks Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 4.5" | 0" | ❄️ Dormant |
| Feb | 3.5" | 4.5" | 0" | ✅ Rainfall sufficient |
| Mar | 3.5" | 5.8" | 0" | ✅ Rainfall sufficient |
| Apr | 3.5" | 4.2" | 0" | ✅ Rainfall sufficient |
| May | 3.5" | 5.2" | 0" | ✅ Rainfall sufficient |
| Jun | 3.5" | 4.6" | 0" | ✅ Rainfall sufficient |
| Jul | 3.5" | 6.8" | 0" | ✅ Rainfall sufficient |
| Aug | 3.5" | 5.3" | 0" | ✅ Rainfall sufficient |
| Sep | 3.5" | 4.2" | 0" | ✅ Rainfall sufficient |
| Oct | 3.5" | 4.1" | 0" | ✅ Rainfall sufficient |
| Nov | 3.5" | 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.
Leeks 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.
Leeks Planting Timeline — St. Tammany Parish, LA
Leeks 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 |
| Harvest | May 22 | May 22 – Aug 7 |
| Fall Sowing | September 28 | Sep 28 – Oct 12 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors Direct Sow |
| February | Start Indoors Transplant Outdoors Direct Sow |
| March | Transplant Outdoors |
| April | — |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | Fall Sowing |
| October | Fall Sowing |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.8"/week · Natural rainfall sufficient
📅 Days to Maturity
90–150 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 Leeks in St. Tammany Parish
Direct sow Leeks 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 Leeks 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 Leeks and water deeply in the morning.
Common pests for Leeks in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.
General growing tips
Start seeds indoors 10-12 weeks before last frost. Transplant into trenches and hill soil around stems as they grow to increase the white portion. Harvest as needed.
Companion Planting
Good Companions
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Leeks in Other Locations
Frequently Asked Questions
When should I plant Leeks in St. Tammany Parish, LA?
St. Tammany Parish is in Zone 9a with an average last frost of February 20. Plan your Leeks 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.