When to Plant Edamame in Jefferson County, ID
Edamame are soybeans harvested at the immature green stage for a sweet, nutty snack. They are high in protein and easy to grow in warm climates.
Jefferson County, Idaho is in USDA Zone 5a. The average last spring frost is May 22 and the first fall frost is September 21, giving you a growing season of approximately 122 days.
At an elevation of 5,094 feet, Jefferson County receives approximately 18 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Edamame during the growing season. With low rainfall, drip irrigation is essential for growing Edamame successfully. Mulch heavily to conserve soil moisture.
Jefferson County Soil Profile
Soil Type
Loam
Soil pH
6.3-7.8
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 Jefferson County
How your county's soil matches Edamame's growing requirements.
Soil pH
Your soil pH (6.3–7.8) is more alkaline than Edamame prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Jefferson County is excellent for Edamame — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.4%). Annual compost additions will help Edamame.
How to Plant Edamame
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Edamame
Edamame needs approximately 0.9 inches of water per week (3.9" per month). Here's how your county's rainfall compares month by month.
| Month | Edamame Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.1" | 0" | ❄️ Dormant |
| Feb | — | 1.2" | 0" | ❄️ Dormant |
| Mar | — | 1.4" | 0" | ❄️ Dormant |
| Apr | — | 2" | 0" | ❄️ Dormant |
| May | 3.9" | 1.9" | 2" | 🚿 Regular watering |
| Jun | 3.9" | 1.4" | 2.5" | 🚿 Regular watering |
| Jul | 3.9" | 1.4" | 2.5" | 🚿 Regular watering |
| Aug | 3.9" | 2" | 1.9" | 💧 Light watering |
| Sep | 3.9" | 1.6" | 2.3" | 🚿 Regular watering |
| Oct | — | 1.6" | 0" | ❄️ Dormant |
| Nov | — | 1.3" | 0" | ❄️ Dormant |
| Dec | — | 1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Jefferson County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Edamame 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.
Edamame Planting Timeline — Jefferson County, ID
Edamame Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | May 29 | May 29 – Jun 19 |
| Harvest | August 14 | Aug 14 – Sep 25 |
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 | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.9"/week · 1-2 times/week
📅 Days to Maturity
75–100 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 5a
📆 Growing Season
122 days in Jefferson County
Growing Tips for Edamame in Jefferson County
Direct sow Edamame outdoors after May 22 in Jefferson County when soil has warmed and frost danger has passed.
Common pests for Edamame in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.
Jefferson County receives only 18" of rain annually. Edamame needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Direct sow after soil is warm. Do not over-fertilize with nitrogen. Harvest when pods are plump and bright green but before they start to yellow. Steam or boil pods before eating.
Companion Planting
Good Companions
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Check more plant combinations with our Companion Planting Checker →
Edamame in Other Locations
Frequently Asked Questions
When should I plant Edamame in Jefferson County, ID?
Jefferson County is in Zone 5a with an average last frost of May 22. Plan your Edamame planting based on this frost date — see the calendar above for exact timing.
What planting zone is Jefferson County, ID?
Jefferson County, Idaho is in USDA Hardiness Zone 5a. The average last spring frost is May 22 and first fall frost is September 21.
Plan Your Garden with Confidence
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