When to Plant Soybeans in Washington County, MS
Your May planting checklist for Washington County, Mississippi
A quick May briefing for Washington County, Mississippi gardeners — what's urgent, what's next, and what can wait.
Get ahead of 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.
Washington County, Mississippi is in USDA Zone 8b. The average last spring frost is March 6 and the first fall frost is November 15, giving you a growing season of approximately 254 days.
At an elevation of 258 feet, Washington County receives approximately 55.3 inches of rainfall annually with predominantly clay loam soil. Summer highs average 90°F, providing good warmth for Soybeans during the growing season. Clay soil retains moisture well for Soybeans, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Soybeans root diseases.
Washington County Soil Profile
Soil Type
Clay Loam
Soil pH
5.4-6.4
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 Washington County
How your county's soil matches Soybeans's growing requirements.
Soil pH
Your soil pH (5.4–6.4) is more acidic than Soybeans prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
The clay loam soil in Washington County is excellent for Soybeans — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.6%). Annual compost additions will help Soybeans.
How to Plant Soybeans
Succession Planting Soybeans
Sow every 9.1 weeks. Last sowing by Jul 18 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 | — | 4.1" | 0" | ❄️ Dormant |
| Feb | — | 4.3" | 0" | ❄️ Dormant |
| Mar | 4.3" | 5.5" | 0" | ✅ Rainfall sufficient |
| Apr | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| May | 4.3" | 4.6" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 5.2" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 6.1" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 5.6" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Oct | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Nov | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Dec | — | 3.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Washington County). 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 — Washington County, MS
Soybeans Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | March 13 | Mar 13 – Apr 3 |
| Harvest | June 5 | Jun 5 – Jul 31 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Direct Sow |
| April | Direct Sow |
| May | — |
| 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 8b
📆 Growing Season
254 days in Washington County
Growing Tips for Soybeans in Washington County
Direct sow Soybeans outdoors after March 06 in Washington County when soil has warmed and frost danger has passed.
With Washington County's clay soil (30% clay), work in 3-4 inches of compost before planting Soybeans. Avoid tilling when soil is wet to prevent compaction.
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 Washington County, MS?
Washington County is in Zone 8b with an average last frost of March 6. Plan your Soybeans planting based on this frost date — see the calendar above for exact timing.
What planting zone is Washington County, MS?
Washington County, Mississippi is in USDA Hardiness Zone 8b. The average last spring frost is March 6 and first fall frost is November 15.
Your Washington County Garden Planner — Free
A 24-page printable planner built for Washington County (Zone 8b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.