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When to Plant Yard Long Beans in Des Moines County, IA

Des Moines County, Iowa Zone 6a May

Your May game plan for Des Moines County, Iowa

May is a pivotal month for Des Moines County, Iowa gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 17
Avg. first frost October 16
Soil temp (4") 57°F
Watering Low
Pest pressure Low
Daylight 14.3 hrs
  1. Plant out yard long beans

    Frost risk is low now in Des Moines County, Iowa. If you've been covering beds overnight, you can stop.

Coming up in June — start thinking about
  • Starting indoors: yard long beans
  • First harvests: yard long beans

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Yard long beans are a tropical legume that produces slender pods up to 24 inches long. They are a staple in Southeast Asian cooking and thrive in hot weather.

Des Moines County, Iowa is in USDA Zone 6a. The average last spring frost is April 17 and the first fall frost is October 16, giving you a growing season of approximately 182 days.

At an elevation of 606 feet, Des Moines County receives approximately 38.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Yard Long Beans during the growing season.

Des Moines County, IA (Zone 6a) Moderate season
182 days
Last Spring Frost April 17
182 growing days
First Fall Frost October 16

Des Moines County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (70 days to spare)
Start indoors: Feb 15 Transplant: Apr 26 🍅 Harvest: Jun 21 – Aug 2
Recommended (50%) ✓ Fits season (70 days to spare)
Start indoors: Feb 20 Transplant: May 1 🍅 Harvest: Jun 26 – Aug 7
Safe Start (90%) ✓ Fits season (69 days to spare)
Start indoors: Mar 8 Transplant: May 17 🍅 Harvest: Jul 12 – Aug 23

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 Des Moines County

How your county's soil matches Yard Long Beans's growing requirements.

Soil pH

Your soil pH (6.2–6.7) is within Yard Long Beans's preferred range (6.0–7.5).

Soil Texture

The silt loam soil in Des Moines County is excellent for Yard Long Beans — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Yard Long Beans.

Organic Matter

Organic matter is moderate (4.0%). Annual compost additions will help Yard Long Beans.

How to Plant Yard Long Beans

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

Succession Planting Yard Long Beans

3
successive plantings in your 182-day season

Sow every 6.3 weeks. Last sowing by Jul 28 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 786 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Yard Long Beans

Yard Long Beans needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Yard Long Beans Needs Rainfall You Supplement Action
Jan 1.8" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 4.3" 3.3" 1" 💧 Light watering
May 4.3" 4" 0.3" 💧 Light watering
Jun 4.3" 5.4" 0" ✅ Rainfall sufficient
Jul 4.3" 4.8" 0" ✅ Rainfall sufficient
Aug 4.3" 4.6" 0" ✅ Rainfall sufficient
Sep 4.3" 3.1" 1.2" 💧 Light watering
Oct 4.3" 2.7" 1.6" 💧 Light watering
Nov 2.9" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Des Moines County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Yard Long Beans 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.

Yard Long Beans needs ~928 GDD — county provides 2,502 GDD Excellent fit

Yard Long Beans Planting Timeline — Des Moines County, IA

Yard Long Beans Planting Calendar

Activity When Date Range
Start Indoors February 20 Feb 20 – Mar 6
Transplant Outdoors May 1 May 1 – May 15
Direct Sow April 24 Apr 24 – May 15
Harvest June 26 Jun 26 – Aug 7

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors
April Direct Sow
May Transplant Outdoors Direct Sow
June Harvest
July Harvest
August Harvest
September
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

55–80 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 6a

📆 Growing Season

182 days in Des Moines County

Growing Tips for Yard Long Beans in Des Moines County

Direct sow Yard Long Beans outdoors after April 17 in Des Moines County when soil has warmed and frost danger has passed.

Common pests for Yard Long Beans 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. Provide tall poles or trellising as vines can reach 8-10 feet. Harvest when pods are pencil-thick before seeds bulge. Cook quickly for best texture.

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 Yard Long Beans in Des Moines County, IA?

Des Moines County is in Zone 6a with an average last frost of April 17. Plan your Yard Long Beans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Des Moines County, IA?

Des Moines County, Iowa is in USDA Hardiness Zone 6a. The average last spring frost is April 17 and first fall frost is October 16.

🌱

Your Des Moines County Garden Planner — Free

A 24-page printable planner built for Des Moines County (Zone 6a). 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 Des Moines County, IA. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.