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When to Plant Edamame in Lafayette County, WI

Lafayette County, Wisconsin Zone 5a May

May to-do list for Lafayette County, Wisconsin

Your garden in Lafayette County, Wisconsin is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost April 28
Avg. first frost October 9
Soil temp (4") 55°F
Watering Moderate
Pest pressure Low
Daylight 14.4 hrs
  1. Outdoor sowing time: edamame

    Keep the top inch of soil moist until germination — a gentle morning watering for 5–7 days does the job.

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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.

Lafayette County, Wisconsin is in USDA Zone 5a. The average last spring frost is April 28 and the first fall frost is October 9, giving you a growing season of approximately 164 days.

At an elevation of 665 feet, Lafayette County receives approximately 31.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Edamame to ensure they mature before fall.

Lafayette County, WI (Zone 5a) Moderate season
164 days
Last Spring Frost April 28
164 growing days
First Fall Frost October 9

Lafayette County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (44 days to spare)
Transplant: Apr 24 🍅 Harvest: Jul 10 – Aug 21
Recommended (50%) ✓ Fits season (45 days to spare)
Transplant: Apr 28 🍅 Harvest: Jul 14 – Aug 25
Safe Start (90%) ✓ Fits season (42 days to spare)
Transplant: May 12 🍅 Harvest: Jul 28 – Sep 8

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 Lafayette County

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

Soil pH

Your soil pH (5.7–7.3) overlaps with Edamame's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Lafayette County is excellent for Edamame — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.9%). Annual compost additions will help Edamame.

How to Plant Edamame

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

Succession Planting Edamame

2
successive plantings in your 164-day season

Sow every 8.6 weeks. Last sowing by Jul 01 to harvest before frost.

Plant Water Budget

Plant needs
0.9″/week
Rainfall provides
0.8″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 159 gal / 100 sq ft
Drought risk

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 1.4" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 3.9" 3.1" 0.8" 💧 Light watering
May 3.9" 3.7" 0.2" 💧 Light watering
Jun 3.9" 4.4" 0" ✅ Rainfall sufficient
Jul 3.9" 3.6" 0.3" 💧 Light watering
Aug 3.9" 3.4" 0.5" 💧 Light watering
Sep 3.9" 2.9" 1" 💧 Light watering
Oct 3.9" 2.2" 1.7" 💧 Light watering
Nov 1.8" 0" ❄️ Dormant
Dec 1.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Lafayette 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 needs ~1,072 GDD — county provides 2,009 GDD Excellent fit

Edamame Planting Timeline — Lafayette County, WI

Edamame Planting Calendar

Activity When Date Range
Direct Sow May 5 May 5 – May 26
Harvest July 21 Jul 21 – Sep 1

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

Month-by-Month Timeline

MonthActivities
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

0.9"/week · Only during dry spells

📅 Days to Maturity

75–100 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

164 days in Lafayette County

Growing Tips for Edamame in Lafayette County

Direct sow Edamame outdoors after April 28 in Lafayette 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 Lafayette County, WI?

Lafayette County is in Zone 5a with an average last frost of April 28. Plan your Edamame planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lafayette County, WI?

Lafayette County, Wisconsin is in USDA Hardiness Zone 5a. The average last spring frost is April 28 and first fall frost is October 9.

🌱

Your Lafayette County Garden Planner — Free

A 24-page printable planner built for Lafayette County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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

Sources & credits

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