When to plant Soybeans in Compton, MD
Compton sits in USDA Zone 8a. Plant Soybeans between April 12 (after last frost on April 5) and May 3.
When to Plant Soybeans in Compton, MD
Your June game plan for St. Mary's County, Maryland
Welcome to June in Zone 8a. These are the moves that will have the biggest impact on your growing season.
Coming up in July — start thinking about
- 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.
Compton, Maryland is in USDA Zone 8a. The average last spring frost is April 5 and the first fall frost is November 4, giving you a growing season of approximately 213 days.
At an elevation of 156 feet, St. Mary's County receives approximately 41.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 92°F, providing good warmth for Soybeans during the growing season.
Compton Soil Profile
Soil Type
Silt Loam
Soil pH
5.5-6.9
Drainage
Well Drained
Soybeans 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 Compton
How your county's soil matches Soybeans's growing requirements.
Soil pH
Your soil pH (5.5–6.9) overlaps with Soybeans's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in St. Mary's County is excellent for Soybeans — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.0%). Annual compost additions will help Soybeans.
How to Plant Soybeans
Succession Planting Soybeans
Sow every 9.1 weeks. Last sowing by Jul 07 to harvest before frost.
Soybeans 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 | — | 3.1" | 0" | ❄️ Dormant |
| Feb | — | 2.6" | 0" | ❄️ Dormant |
| Mar | — | 3.3" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.3" | 1" | 💧 Light watering |
| May | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Jun | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4" | 0.3" | 💧 Light watering |
| Aug | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Oct | 4.3" | 3.4" | 0.9" | 💧 Light watering |
| Nov | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| Dec | — | 2.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Nov in St. Mary's 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 — Compton, MD
Soybeans Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | April 12 | Apr 12 – May 3 |
| Harvest | July 5 | Jul 5 – Aug 30 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Direct Sow |
| May | Direct Sow |
| June | — |
| July | Harvest |
| August | Harvest |
| 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: acceptable
🗺️ USDA Zone
Zone 8a
📆 Growing Season
213 days in St. Mary's County
Growing Tips for Soybeans in Compton
Direct sow Soybeans outdoors after April 05 in St. Mary's 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
When should I plant Soybeans in Compton, MD?
In Compton, MD, plant Soybeans after the last frost (around April 5) and before the first frost (around November 4). Best results when soil holds above 50°F.
What growing zone is Compton, MD for Soybeans?
Compton sits in USDA Zone 8a. Soybeans grows reliably in zones 3a through 10b, so it's a good fit here.
Can Soybeans grow in Compton's climate?
Yes — Soybeans grows well in Compton's temperate climate. Compton averages a 213-day frost-free season, with last frost around April 5 and first frost around November 4.
Your St. Mary's County Garden Planner — Free
A 22-page printable planner built for St. Mary's County (Zone 8a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.