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When to plant Peppers in Putnam County, IL

For Putnam County, gardeners: plant Peppers April 28 through May 19 once soil reads 50°F.

When to Plant Peppers in Putnam County, IL

Peppers

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.

Putnam County, Illinois is in USDA Zone 5b. The average last spring frost is April 21 and the first fall frost is October 13, giving you a growing season of approximately 175 days.

At an elevation of 582 feet, Putnam County receives approximately 41.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Peppers during the growing season.

Putnam County, IL (Zone 5b) Moderate season
175 days
Last Spring Frost April 21
175 growing days
First Fall Frost October 13

Putnam County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.7

Drainage

Well Drained

How Much Peppers to Grow

3-5 lbs
Average yield per plant
3
Plants per person
6 sq ft
Space per person

For a family of 4, plant approximately 12 peppers plants in about 24 sq ft. In Putnam County's 175-day season, you'll have plenty of time for a full harvest. Plan your garden layout →

Monthly Watering Guide for Peppers

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

Month Peppers Needs Rainfall You Supplement Action
Jan 1.8" 0" ❄️ Dormant
Feb 2" 0" ❄️ Dormant
Mar 3.1" 0" ❄️ Dormant
Apr 4.3" 3.6" 0.7" 💧 Light watering
May 4.3" 4.3" 0" ✅ Rainfall sufficient
Jun 4.3" 5.2" 0" ✅ Rainfall sufficient
Jul 4.3" 5" 0" ✅ Rainfall sufficient
Aug 4.3" 4.3" 0" ✅ Rainfall sufficient
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 3.3" 1" 💧 Light watering
Nov 3.2" 0" ❄️ Dormant
Dec 2.5" 0" ❄️ Dormant

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

Peppers Planting Timeline — Putnam County, IL

Peppers Planting Calendar

Activity When Date Range
Start Indoors February 10 Feb 10 – Feb 24
Transplant Outdoors May 5 May 5 – May 19
Direct Sow April 28 Apr 28 – May 19
Harvest July 7 Jul 7 – Sep 15

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 5b

📆 Growing Season

175 days in Putnam County

Growing Tips for Putnam County

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 Putnam County, IL?

Putnam County is in Zone 5b with an average last frost of April 21. Plan your Peppers planting based on this frost date — see the calendar above for exact timing.

What planting zone is Putnam County, IL?

Putnam County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 21 and first fall frost is October 13.

When should I plant Peppers in Putnam County, IL?

In Putnam County, IL, plant Peppers after the last frost (around April 21) and before the first frost (around October 13). Best results when soil holds above 50°F.

What growing zone is Putnam County, IL for Peppers?

Putnam County sits in USDA Zone 5b. Peppers grows reliably in zones 3a through 11b, so it's a good fit here.

Can Peppers grow in Putnam County's climate?

Yes — Peppers grows well in Putnam County's temperate climate. Putnam County averages a 175-day frost-free season, with last frost around April 21 and first frost around October 13.

🌱

Your Putnam County Garden Planner — Free

A 22-page printable planner built for Putnam 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.

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 Putnam County, IL. Local conditions may vary. Last updated: July 2026.

Sources & credits

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