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When to Plant Peppers in Guthrie County, IA

Guthrie County, Iowa Zone 5a April

Top priorities for Guthrie County, Iowa gardeners in April

Each item below is timed to Guthrie County, Iowa's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 26
Avg. first frost October 6
Soil temp (4") 43°F
Watering Moderate
Pest pressure Low
Daylight 13.1 hrs
Before May arrives, get these ready
  • Transplants going out: peppers
  • Direct-sowing: peppers

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Sweet peppers are warm-season crops producing fruits in a rainbow of colors. They turn from green to red, yellow, or orange as they ripen, increasing in sweetness.

Guthrie County, Iowa is in USDA Zone 5a. The average last spring frost is April 26 and the first fall frost is October 6, giving you a growing season of approximately 163 days.

At an elevation of 1,378 feet, Guthrie County receives approximately 31.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Peppers to ensure they mature before fall.

Guthrie County, IA (Zone 5a) Moderate season
163 days
Last Spring Frost April 26
163 growing days
First Fall Frost October 6
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Guthrie County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (16 days to spare)
Start indoors: Feb 11 Transplant: May 6 🍅 Harvest: Jul 8 – Sep 16
Recommended (50%) ✓ Fits season (16 days to spare)
Start indoors: Feb 15 Transplant: May 10 🍅 Harvest: Jul 12 – Sep 20
Safe Start (90%) ✓ Fits season (16 days to spare)
Start indoors: Mar 2 Transplant: May 25 🍅 Harvest: Jul 27 – Oct 5

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 Guthrie County

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

Soil pH

Your soil pH (5.9–6.7) overlaps with Peppers's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.1%) — Peppers will thrive.

How to Plant Peppers

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

Succession Planting Peppers

3
successive plantings in your 163-day season

Sow every 6.9 weeks. Last sowing by Jul 08 to harvest before frost.

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
0.8″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 411 gal / 100 sq ft

Monthly Watering Guide for Peppers

Peppers needs approximately 1.1 inches of water per week (4.8" per month). Here's how your county's rainfall compares month by month.

Month Peppers Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 4.8" 3.1" 1.7" 💧 Light watering
May 4.8" 3.5" 1.3" 💧 Light watering
Jun 4.8" 3.6" 1.2" 💧 Light watering
Jul 4.8" 3.6" 1.2" 💧 Light watering
Aug 4.8" 3.4" 1.4" 💧 Light watering
Sep 4.8" 3" 1.8" 💧 Light watering
Oct 4.8" 2.3" 2.5" 🚿 Regular watering
Nov 2" 0" ❄️ Dormant
Dec 1.6" 0" ❄️ Dormant

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

Peppers 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.

Peppers needs ~919 GDD — county provides 1,996 GDD Excellent fit

Peppers Planting Timeline — Guthrie County, IA

Peppers Planting Calendar

Activity When Date Range
Start Indoors February 15 Feb 15 – Mar 1
Transplant Outdoors May 10 May 10 – May 24
Direct Sow May 3 May 3 – May 24
Harvest July 12 Jul 12 – Sep 20

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.1"/week · Only during dry spells

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

163 days in Guthrie County

Growing Tips for Peppers in Guthrie County

Direct sow Peppers outdoors after April 26 in Guthrie County when soil has warmed and frost danger has passed.

Common pests for Peppers in this region include tomato hornworm and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 8-10 weeks before last frost. Transplant when nighttime temperatures stay above 55F. Avoid high-nitrogen fertilizers which promote leaves over fruit.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel
  • Kohlrabi

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Peppers Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Remove seeds from fully ripe (red/orange) fruit.
Storage Store airtight; viable 4 years at 35°F, under 50% humidity.

Isolate 300 ft for purity. Hot and sweet peppers can cross-pollinate.

Frequently Asked Questions

When should I plant Peppers in Guthrie County, IA?

Guthrie County is in Zone 5a with an average last frost of April 26. Plan your Peppers planting based on this frost date — see the calendar above for exact timing.

What planting zone is Guthrie County, IA?

Guthrie County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 26 and first fall frost is October 6.

🌱

Your Guthrie County Garden Planner — Free

A 24-page printable planner built for Guthrie 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 Guthrie County, IA. Local conditions may vary. Last updated: April 2026.

Sources & credits

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