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When to Plant Edamame in Edgar County, IL

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.

Edgar County, Illinois is in USDA Zone 5b. The average last spring frost is April 18 and the first fall frost is October 17, giving you a growing season of approximately 182 days.

At an elevation of 1,272 feet, Edgar County receives approximately 41.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Edamame to ensure they mature before fall.

Edgar County, IL (Zone 5b) Moderate season
182 days
Last Spring Frost April 18
182 growing days
First Fall Frost October 17

Edgar County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (62 days to spare)
Transplant: Apr 13 🍅 Harvest: Jun 29 – Aug 10
Recommended (50%) ✓ Fits season (63 days to spare)
Transplant: Apr 18 🍅 Harvest: Jul 4 – Aug 15
Safe Start (90%) ✓ Fits season (60 days to spare)
Transplant: May 4 🍅 Harvest: Jul 20 – Aug 31

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 Edgar County

How your county's soil matches Edamame's growing requirements.

Soil pH

Your soil pH (5.9โ€“6.8) overlaps with Edamame's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

The silt loam soil in Edgar County is excellent for Edamame โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.3%) โ€” Edamame will thrive.

How to Plant Edamame

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Succession Planting Edamame

2
successive plantings in your 182-day season

Sow every 8.6 weeks. Last sowing by Jul 09 to harvest before frost.

Plant Water Budget

Plant needs
0.9″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” 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 โ€” 1.6" 0" โ„๏ธ Dormant
Feb โ€” 1.9" 0" โ„๏ธ Dormant
Mar โ€” 2.8" 0" โ„๏ธ Dormant
Apr 3.9" 3.8" 0.1" ๐Ÿ’ง Light watering
May 3.9" 4.8" 0" โœ… Rainfall sufficient
Jun 3.9" 5.5" 0" โœ… Rainfall sufficient
Jul 3.9" 4.9" 0" โœ… Rainfall sufficient
Aug 3.9" 3.8" 0.1" ๐Ÿ’ง Light watering
Sep 3.9" 3.9" 0" โœ… Rainfall sufficient
Oct 3.9" 3.3" 0.6" ๐Ÿ’ง Light watering
Nov โ€” 2.9" 0" โ„๏ธ Dormant
Dec โ€” 2.1" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Edgar County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 needs ~1,072 GDD — county provides 2,229 GDD Excellent fit

Edamame Planting Timeline โ€” Edgar County, IL

Edamame Planting Calendar

Activity When Date Range
Direct Sow April 25 Apr 25 โ€“ May 16
Harvest July 11 Jul 11 โ€“ Aug 22

Plant 1" deep ยท 15" apart ยท Rows 24" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Direct Sow
May Direct Sow
June โ€”
July Harvest
August Harvest
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.9"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

75โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 5b

๐Ÿ“† Growing Season

182 days in Edgar County

Growing Tips for Edamame in Edgar County

Direct sow Edamame outdoors after April 18 in Edgar 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.

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

Avoid Planting Near

  • Onion
  • Garlic

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Edamame in Edgar County, IL?

Edgar County is in Zone 5b with an average last frost of April 18. Plan your Edamame planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Edgar County, IL?

Edgar County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 18 and first fall frost is October 17.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Edgar County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Edgar County, IL. Local conditions may vary. Last updated: April 2026.