When to Plant Soybeans in Slope County, ND
Your May planting checklist for Slope County, North Dakota
Welcome to May in Zone 4b. These are the moves that will have the biggest impact on your growing season.
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Direct-sow soybeans
Rake a smooth bed, make a shallow furrow, drop seeds at the spacing on the packet, water gently, walk away.
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.
Slope County, North Dakota is in USDA Zone 4b. The average last spring frost is May 15 and the first fall frost is September 24, giving you a growing season of approximately 132 days.
At an elevation of 1,230 feet, Slope County receives approximately 31.4 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Soybeans to ensure they mature before fall.
Slope County Soil Profile
Soil Type
Loam
Soil pH
6.7-7.6
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 Slope County
How your county's soil matches Soybeans's growing requirements.
Soil pH
Your soil pH (6.7–7.6) is more alkaline than Soybeans prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Slope County is excellent for Soybeans — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Soybeans.
Organic Matter
Organic matter is excellent (4.2%) — Soybeans will thrive.
How to Plant Soybeans
Plant Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
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 | — | 1.9" | 0" | ❄️ Dormant |
| Mar | — | 3.1" | 0" | ❄️ Dormant |
| Apr | — | 2.9" | 0" | ❄️ Dormant |
| May | 4.3" | 3.3" | 1" | 💧 Light watering |
| Jun | 4.3" | 2.3" | 2" | 💧 Light watering |
| Jul | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| Aug | 4.3" | 3" | 1.3" | 💧 Light watering |
| Sep | 4.3" | 2.3" | 2" | 💧 Light watering |
| Oct | — | 2.7" | 0" | ❄️ Dormant |
| Nov | — | 2.3" | 0" | ❄️ Dormant |
| Dec | — | 2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Slope 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 — Slope County, ND
Soybeans Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | May 29 | May 29 – Jun 19 |
| Harvest | August 21 | Aug 21 – Oct 16 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Direct Sow |
| June | Direct Sow |
| July | — |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · 1-2 times/week
📅 Days to Maturity
80–120 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 4b
📆 Growing Season
132 days in Slope County
Growing Tips for Soybeans in Slope County
Direct sow Soybeans outdoors after May 15 in Slope County when soil has warmed and frost danger has passed.
Your 132.0-day growing season in Slope County is tight for Soybeans (80.0-120.0 days to maturity). Start indoors and choose early-maturing varieties.
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 Slope County, ND?
Slope County is in Zone 4b with an average last frost of May 15. Plan your Soybeans planting based on this frost date — see the calendar above for exact timing.
What planting zone is Slope County, ND?
Slope County, North Dakota is in USDA Hardiness Zone 4b. The average last spring frost is May 15 and first fall frost is September 24.
Your Slope County Garden Planner — Free
A 24-page printable planner built for Slope County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.