Blog

When to Plant Peas in Calhoun County, IA

Calhoun County, Iowa Zone 5a May

May to-do list for Calhoun County, Iowa

Your Calhoun 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 April 25
Avg. first frost October 6
Soil temp (4") 54°F
Watering Moderate
Pest pressure Low
Daylight 14.4 hrs
  1. Indoor seed-starting week for peas

    Label every cell. You will absolutely forget which is which otherwise.

Looking ahead to June
  • First harvests: peas

Instant PDF download. No spam, unsubscribe any time.

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.

Calhoun County, Iowa is in USDA Zone 5a. The average last spring frost is April 25 and the first fall frost is October 6, giving you a growing season of approximately 164 days.

At an elevation of 1,052 feet, Calhoun County receives approximately 30.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 82°F, so choose short-season varieties of Peas to ensure they mature before fall.

Calhoun County, IA (Zone 5a) Moderate season
164 days
Last Spring Frost April 25
164 growing days
First Fall Frost October 6

Calhoun County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (52 days to spare)
Start indoors: Mar 17 Transplant: Apr 21 🍅 Harvest: Jun 16 – Aug 11
Recommended (50%) ✓ Fits season (52 days to spare)
Start indoors: Mar 21 Transplant: Apr 25 🍅 Harvest: Jun 20 – Aug 15
Safe Start (90%) ✓ Fits season (52 days to spare)
Start indoors: Apr 5 Transplant: May 10 🍅 Harvest: Jul 5 – Aug 30

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 Calhoun County

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

Soil pH

Your soil pH (5.8–6.8) overlaps with Peas's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.5%) — 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 164-day season

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

For a dedicated fall crop, sow by Jul 28.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 1.2" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 3" 3.2" 0" ✅ Rainfall sufficient
May 3" 3.4" 0" ✅ Rainfall sufficient
Jun 3" 3.3" 0" ✅ Rainfall sufficient
Jul 3" 2.9" 0.1" 💧 Light watering
Aug 3" 3.5" 0" ✅ Rainfall sufficient
Sep 3" 2.4" 0.6" 💧 Light watering
Oct 3" 2.7" 0.3" 💧 Light watering
Nov 2.3" 0" ❄️ Dormant
Dec 1.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Calhoun 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 ~719 GDD — county provides 1,886 GDD Excellent fit

Peas Planting Timeline — Calhoun County, IA

Peas Planting Calendar

Activity When Date Range
Start Indoors March 21 Mar 21 – Apr 4
Transplant Outdoors April 25 Apr 25 – May 9
Direct Sow April 11 Apr 11 – May 2
Harvest June 20 Jun 20 – Aug 15
Fall Sowing July 28 Jul 28 – Aug 11

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors Transplant Outdoors 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 · Natural rainfall sufficient

📅 Days to Maturity

55–70 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

164 days in Calhoun County

Growing Tips for Peas in Calhoun County

Direct sow Peas outdoors after April 25 in Calhoun 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.

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 Calhoun County, IA?

Calhoun County is in Zone 5a with an average last frost of April 25. Plan your Peas planting based on this frost date — see the calendar above for exact timing.

What planting zone is Calhoun County, IA?

Calhoun County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 25 and first fall frost is October 6.

🌱

Your Calhoun County Garden Planner — Free

A 24-page printable planner built for Calhoun 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.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Calhoun 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.