When to Plant Soybeans in Greater Sudbury, ON
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.
Greater Sudbury, Ontario is in USDA Zone 5b. The average last spring frost is April 24 and the first fall frost is October 8, giving you a growing season of approximately 167 days.
At an elevation of 1,141 feet, Greater Sudbury receives approximately 29.7 inches of rainfall annually with predominantly clay loam soil. Summer highs average 77°F, so choose short-season varieties of Soybeans to ensure they mature before fall. Clay soil retains moisture well for Soybeans, but amend with compost to improve drainage and prevent root rot.
Greater Sudbury Soil Profile
Soil Type
Clay Loam
Soil pH
6.0-7.0
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.
How to Plant Soybeans
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 | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 2.3" | 0" | ❄️ Dormant |
| Apr | 4.3" | 2.9" | 1.4" | 💧 Light watering |
| May | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Jun | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Jul | 4.3" | 3.4" | 0.9" | 💧 Light watering |
| Aug | 4.3" | 3" | 1.3" | 💧 Light watering |
| Sep | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| Oct | 4.3" | 2" | 2.3" | 🚿 Regular watering |
| Nov | — | 1.8" | 0" | ❄️ Dormant |
| Dec | — | 1.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Greater Sudbury). 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 — Greater Sudbury, ON
Soybeans Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | May 1 | May 1 – May 22 |
| Harvest | July 24 | Jul 24 – Sep 18 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Direct Sow |
| June | — |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| 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: N/A
🗺️ USDA Zone
Zone 5b
📆 Growing Season
167 days in Greater Sudbury
Growing Tips for Soybeans in Greater Sudbury
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
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Soybeans in Other Locations
Frequently Asked Questions
When should I plant Soybeans in Greater Sudbury, ON?
Greater Sudbury is in Zone 5b with an average last frost of April 24. Plan your Soybeans planting based on this frost date — see the calendar above for exact timing.
What planting zone is Greater Sudbury, ON?
Greater Sudbury, Ontario is in USDA Hardiness Zone 5b. The average last spring frost is April 24 and first fall frost is October 8.
Plan Your Garden with Confidence
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