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When to Plant Peas in Polk County, IA

Polk County, Iowa Zone 5b May

Your May game plan for Polk County, Iowa

Your Polk County, Iowa garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost May 2
Avg. first frost October 7
Soil temp (4") 59°F
Watering Low
Pest pressure Low
Daylight 14.4 hrs
  1. Time to transplant peas

    Your last frost (May 2) has passed. These warm-season crops can handle outdoor soil now.

Get ahead of June
  • Starting indoors: peas
  • First harvests: peas

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Peas are a cool-season legume that fixes nitrogen in the soil. Garden peas are shelled, while snap and snow peas are eaten pod and all.

Polk County, Iowa is in USDA Zone 5b. 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 1,037 feet, Polk County receives approximately 30.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Peas during the growing season.

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

Polk County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (47 days to spare)
Start indoors: Mar 18 Transplant: Apr 22 🍅 Harvest: Jun 17 – Aug 12
Recommended (50%) ✓ Fits season (46 days to spare)
Start indoors: Mar 28 Transplant: May 2 🍅 Harvest: Jun 27 – Aug 22
Safe Start (90%) ✓ Fits season (45 days to spare)
Start indoors: Apr 7 Transplant: May 12 🍅 Harvest: Jul 7 – Sep 1

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 Polk County

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

Soil pH

Your soil pH (6.0–6.8) is within Peas's preferred range (6.0–7.5).

Soil Texture

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

Drainage

Drainage is adequate for Peas.

Organic Matter

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

How to Plant Peas

1"
Planting Depth
4"
Between Plants
18"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Peas

3
successive plantings in your 158-day season

Sow every 6.3 weeks. Last sowing by Jul 29 to harvest before frost.

For a dedicated fall crop, sow by Jul 29.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.8″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 181 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Peas

Peas needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Peas Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 2.6" 0" ❄️ Dormant
May 3" 3.9" 0" ✅ Rainfall sufficient
Jun 3" 4.1" 0" ✅ Rainfall sufficient
Jul 3" 3.3" 0" ✅ Rainfall sufficient
Aug 3" 3.1" 0" ✅ Rainfall sufficient
Sep 3" 3.1" 0" ✅ Rainfall sufficient
Oct 3" 2.1" 0.9" 💧 Light watering
Nov 1.9" 0" ❄️ Dormant
Dec 1.6" 0" ❄️ Dormant

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

Peas 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.

Peas needs ~906 GDD — county provides 2,291 GDD Excellent fit

Peas Planting Timeline — Polk County, IA

Peas Planting Calendar

Activity When Date Range
Start Indoors March 28 Mar 28 – Apr 11
Transplant Outdoors May 2 May 2 – May 16
Direct Sow April 18 Apr 18 – May 9
Harvest June 27 Jun 27 – Aug 22
Fall Sowing July 29 Jul 29 – Aug 12

Plant 1" deep · 4" apart · Rows 18" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.7"/week · Only during dry spells

📅 Days to Maturity

55–70 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 5b

📆 Growing Season

158 days in Polk County

Growing Tips for Peas in Polk County

Direct sow Peas outdoors after May 02 in Polk County when soil has warmed and frost danger has passed.

Common pests for Peas in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow as early as soil can be worked in spring. Inoculate seeds with rhizobium for best nitrogen fixation. Provide trellising for climbing varieties.

Recommended Peas Varieties for Polk County

Heat-tolerant peas — plant very early or as fall crop

Wando (68d) Oregon Sugar Pod (60d)

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Peas Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Let pods dry brown and papery on the vine.
Storage Store airtight; viable 3 years at 35°F, under 45% humidity.

Very easy to save. Self-pollinating means varieties stay true.

Frequently Asked Questions

When should I plant Peas in Polk County, IA?

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

What planting zone is Polk County, IA?

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

🌱

Your Polk County Garden Planner — Free

A 24-page printable planner built for Polk County (Zone 5b). 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 Polk 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.