When to Plant Soybeans in Lafayette Parish, LA
Your May planting checklist for Lafayette Parish, Louisiana
If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.
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Basket week: soybeans
Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.
A few tasks this May that'll pay off in June
- First harvests: soybeans
Soybeans (edamame) are a high-protein legume that fixes nitrogen in the soil. Fresh green soybeans harvested at the edamame stage are a nutritious snack.
Lafayette Parish, Louisiana is in USDA Zone 9a. The average last spring frost is February 13 and the first fall frost is December 5, giving you a growing season of approximately 295 days.
At an elevation of 129 feet, Lafayette Parish receives approximately 48.9 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 104°F, so Soybeans may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Soybeans will need more frequent watering and organic matter to retain nutrients.
Lafayette Parish Soil Profile
Soil Type
Sandy Loam
Soil pH
4.8-6.4
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 Lafayette Parish
How your county's soil matches Soybeans's growing requirements.
Soil pH
Your soil pH (4.8–6.4) is more acidic than Soybeans prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
Sandy soil in Lafayette Parish warms quickly in spring but drains fast. Soybeans will need more frequent watering and regular compost additions to retain nutrients.
Drainage
Drainage is adequate for Soybeans.
Organic Matter
Organic matter is low (1.8%). Add 2-3 inches of compost before planting Soybeans.
How to Plant Soybeans
Succession Planting Soybeans
Sow every 9.1 weeks. Last sowing by Aug 07 to harvest before frost.
Plant Water Budget
Monthly Watering Guide for Soybeans
Soybeans needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Soybeans Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 3.6" | 0" | ❄️ Dormant |
| Feb | 4.3" | 3.4" | 0.9" | 💧 Light watering |
| Mar | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Apr | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| May | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 4.8" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Oct | 4.3" | 3.4" | 0.9" | 💧 Light watering |
| Nov | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Dec | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
Water needs are for active growing months only (Feb–Dec in Lafayette Parish). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Soybeans 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.
Soybeans Planting Timeline — Lafayette Parish, LA
Soybeans Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | February 20 | Feb 20 – Mar 13 |
| Harvest | May 15 | May 15 – Jul 10 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Direct Sow |
| March | Direct Sow |
| April | — |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
80–120 days
🧪 Soil pH
Needs 6–7 · Your soil: too_acidic
🗺️ USDA Zone
Zone 9a
📆 Growing Season
295 days in Lafayette Parish
Growing Tips for Soybeans in Lafayette Parish
Direct sow Soybeans outdoors after February 13 in Lafayette Parish when soil has warmed and frost danger has passed.
Sandy soil in Lafayette Parish dries quickly — mulch Soybeans with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
With summer highs reaching 104°F in Lafayette Parish, provide afternoon shade for Soybeans and water deeply in the morning.
Common pests for Soybeans in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.
General growing tips
Direct sow after soil warms to 60F. Plant in blocks rather than rows for better pollination. Harvest for edamame when pods are plump and bright green.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Soybeans in Other Locations
Frequently Asked Questions
When should I plant Soybeans in Lafayette Parish, LA?
Lafayette Parish is in Zone 9a with an average last frost of February 13. Plan your Soybeans planting based on this frost date — see the calendar above for exact timing.
What planting zone is Lafayette Parish, LA?
Lafayette Parish, Louisiana is in USDA Hardiness Zone 9a. The average last spring frost is February 13 and first fall frost is December 5.
Your Lafayette Parish Garden Planner — Free
A 24-page printable planner built for Lafayette 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.