When to Plant Soybeans in Alpine County, CA
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.
Alpine County, California is in USDA Zone 5a. The average last spring frost is May 19 and the first fall frost is October 3, giving you a growing season of approximately 137 days.
At an elevation of 1,278 feet, Alpine County receives approximately 36.3 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Soybeans to ensure they mature before fall.
Alpine County Soil Profile
Soil Type
Loam
Soil pH
6.4-7.3
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.
Plant Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Soybeans Planting Timeline — Alpine County, CA
Soybeans Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | May 26 | May 26 – Jun 16 |
| Harvest | August 18 | Aug 18 – Oct 13 |
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
Moderate — regular watering
Days to Maturity
80–120 days
Soil pH
6 – 7
USDA Zone
Zone 5a
Growing Season
137 days
Growing Tips for Alpine County
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
Level Up Your Garden
Soybeans in Other Locations
Frequently Asked Questions
When should I plant Soybeans in Alpine County, CA?
Alpine County is in Zone 5a with an average last frost of May 19. Plan your Soybeans planting based on this frost date — see the calendar above for exact timing.
What planting zone is Alpine County, CA?
Alpine County, California is in USDA Hardiness Zone 5a. The average last spring frost is May 19 and first fall frost is October 3.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Alpine County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.
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