When to plant Soybeans in Saint Augustine, FL
Soybeans planted in Saint Augustine between February 16 and March 9 matures in 80–120 days — well before the December 2 first frost.
When to Plant Soybeans in Saint Augustine, FL
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.
Saint Augustine, Florida is in USDA Zone 9b. The average last spring frost is February 9 and the first fall frost is December 2, giving you a growing season of approximately 296 days.
At an elevation of 57 feet, St. Johns County receives approximately 51.1 inches of rainfall annually with predominantly sand soil. Summer highs average 99°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. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Soybeans root diseases.
Saint Augustine Soil Profile
Soil Type
Sand
Soil pH
4.9-6.1
Drainage
Well Drained
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 | — | 2.4" | 0" | ❄️ Dormant |
| Feb | 4.3" | 2.4" | 1.9" | 💧 Light watering |
| Mar | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| Apr | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| May | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Jun | 4.3" | 7" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 7.1" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 7.6" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 6.9" | 0" | ✅ Rainfall sufficient |
| Oct | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Nov | 4.3" | 2.1" | 2.2" | 🚿 Regular watering |
| Dec | 4.3" | 2.3" | 2" | 💧 Light watering |
Water needs are for active growing months only (Feb–Dec in St. Johns County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Soybeans Planting Timeline — Saint Augustine, FL
Soybeans Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | February 16 | Feb 16 – Mar 9 |
| Harvest | May 11 | May 11 – Jul 6 |
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
Moderate — regular watering
📅 Days to Maturity
80–120 days
🧪 Soil pH
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 9b
📆 Growing Season
296 days in St. Johns County
Growing Tips for Saint Augustine
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
When should I plant Soybeans in Saint Augustine, FL?
In Saint Augustine, FL, plant Soybeans after the last frost (around February 9) and before the first frost (around December 2). Best results when soil holds above 50°F.
What growing zone is Saint Augustine, FL for Soybeans?
Saint Augustine sits in USDA Zone 9b. Soybeans grows reliably in zones 3a through 10b, so it's a good fit here.
Can Soybeans grow in Saint Augustine's climate?
Yes — Soybeans grows well in Saint Augustine's temperate climate. Saint Augustine averages a 297-day frost-free season, with last frost around February 9 and first frost around December 2.
Your St. Johns County Garden Planner — Free
A 22-page printable planner built for St. Johns County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.