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When to Plant Lima Beans in Allamakee County, IA

Allamakee County, Iowa Zone 5a May

Top priorities for Allamakee County, Iowa gardeners in May

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Allamakee County, Iowa.

Avg. last frost May 2
Avg. first frost October 7
Soil temp (4") 54°F
Watering Low
Pest pressure Low
Daylight 14.5 hrs
  1. Outdoor sowing time: lima beans

    These tolerate cool soil, so you're not gambling by sowing now.

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Lima beans are a warm-season legume producing large, creamy beans with a buttery texture. Both bush and pole varieties are available, with pole types yielding more.

Allamakee County, Iowa is in USDA Zone 5a. The average last spring frost is May 2 and the first fall frost is October 7, giving you a growing season of approximately 158 days.

At an elevation of 804 feet, Allamakee County receives approximately 39.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 82°F, so choose short-season varieties of Lima Beans to ensure they mature before fall.

Allamakee County, IA (Zone 5a) Moderate season
158 days
Last Spring Frost May 2
158 growing days
First Fall Frost October 7

Allamakee County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (56 days to spare)
Transplant: Apr 24 🍅 Harvest: Jun 26 – Aug 7
Recommended (50%) ✓ Fits season (53 days to spare)
Transplant: May 2 🍅 Harvest: Jul 4 – Aug 15
Safe Start (90%) ✓ Fits season (52 days to spare)
Transplant: May 15 🍅 Harvest: Jul 17 – Aug 28

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 Allamakee County

How your county's soil matches Lima Beans's growing requirements.

Soil pH

Your soil pH (5.9–7.1) overlaps with Lima Beans's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.7%) — Lima Beans will thrive.

How to Plant Lima Beans

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

Succession Planting Lima Beans

3
successive plantings in your 158-day season

Sow every 6.9 weeks. Last sowing by Jul 09 to harvest before frost.

Plant Water Budget

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

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

Monthly Watering Guide for Lima Beans

Lima Beans 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 Lima Beans Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 4" 0" ❄️ Dormant
May 3.9" 4.3" 0" ✅ Rainfall sufficient
Jun 3.9" 5.3" 0" ✅ Rainfall sufficient
Jul 3.9" 4.6" 0" ✅ Rainfall sufficient
Aug 3.9" 4.2" 0" ✅ Rainfall sufficient
Sep 3.9" 3.4" 0.5" 💧 Light watering
Oct 3.9" 2.9" 1" 💧 Light watering
Nov 3" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

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

Lima 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.

Lima Beans needs ~862 GDD — county provides 1,817 GDD Excellent fit

Lima Beans Planting Timeline — Allamakee County, IA

Lima Beans Planting Calendar

Activity When Date Range
Direct Sow May 9 May 9 – May 30
Harvest July 11 Jul 11 – Aug 22

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
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.9"/week · Natural rainfall sufficient

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

158 days in Allamakee County

Growing Tips for Lima Beans in Allamakee County

Direct sow Lima Beans outdoors after May 02 in Allamakee County when soil has warmed and frost danger has passed.

Common pests for Lima 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 thoroughly warm at 65F or above. Do not soak seeds before planting as they may crack. Harvest when pods are plump but still green for fresh limas.

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic
  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Lima Beans in Allamakee County, IA?

Allamakee County is in Zone 5a with an average last frost of May 2. Plan your Lima Beans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Allamakee County, IA?

Allamakee County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is May 2 and first fall frost is October 7.

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Your Allamakee County Garden Planner — Free

A 24-page printable planner built for Allamakee 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 Allamakee 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.