When to Plant Soybeans in Smyth County, VA
May in Smyth County, Virginia — your action list
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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Sow soybeans where they'll grow
Succession planting is the secret here. Put in a row now, another in 2 weeks, a third in 4.
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.
Smyth County, Virginia is in USDA Zone 7a. The average last spring frost is May 2 and the first fall frost is October 12, giving you a growing season of approximately 163 days.
At an elevation of 375 feet, Smyth County receives approximately 51.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Soybeans during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Soybeans root diseases.
Smyth County Soil Profile
Soil Type
Silt Loam
Soil pH
5.3-6.8
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 Smyth County
How your county's soil matches Soybeans's growing requirements.
Soil pH
Your soil pH (5.3–6.8) overlaps with Soybeans's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Smyth County is excellent for Soybeans — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.5%). Annual compost additions will help Soybeans.
How to Plant Soybeans
Succession Planting Soybeans
Sow every 9.1 weeks. Last sowing by Jun 14 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 | — | 3.9" | 0" | ❄️ Dormant |
| Feb | — | 3.9" | 0" | ❄️ Dormant |
| Mar | — | 4.6" | 0" | ❄️ Dormant |
| Apr | — | 4.3" | 0" | ❄️ Dormant |
| May | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Jun | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Jul | 4.3" | 5.4" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 5.7" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Oct | 4.3" | 3.3" | 1" | 💧 Light watering |
| Nov | — | 3.7" | 0" | ❄️ Dormant |
| Dec | — | 4.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Smyth 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 — Smyth County, VA
Soybeans Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | May 9 | May 9 – May 30 |
| Harvest | August 1 | Aug 1 – Sep 26 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Direct Sow |
| June | — |
| July | — |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Natural rainfall sufficient
📅 Days to Maturity
80–120 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 7a
📆 Growing Season
163 days in Smyth County
Growing Tips for Soybeans in Smyth County
Direct sow Soybeans outdoors after May 02 in Smyth County when soil has warmed and frost danger has passed.
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 Smyth County, VA?
Smyth County is in Zone 7a with an average last frost of May 2. Plan your Soybeans planting based on this frost date — see the calendar above for exact timing.
What planting zone is Smyth County, VA?
Smyth County, Virginia is in USDA Hardiness Zone 7a. The average last spring frost is May 2 and first fall frost is October 12.
Your Smyth County Garden Planner — Free
A 24-page printable planner built for Smyth County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.