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When to Plant Peas in Hamilton County, IL

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.

Hamilton County, Illinois is in USDA Zone 6a. The average last spring frost is April 9 and the first fall frost is October 23, giving you a growing season of approximately 197 days.

At an elevation of 524 feet, Hamilton County receives approximately 39 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90ยฐF, providing good warmth for Peas during the growing season.

Hamilton County, IL (Zone 6a) Moderate season
197 days
Last Spring Frost April 9
197 growing days
First Fall Frost October 23

Hamilton County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (85 days to spare)
Start indoors: Feb 27 Transplant: Apr 3 🍅 Harvest: May 29 – Jul 24
Recommended (50%) ✓ Fits season (85 days to spare)
Start indoors: Mar 5 Transplant: Apr 9 🍅 Harvest: Jun 4 – Jul 30
Safe Start (90%) ✓ Fits season (95 days to spare)
Start indoors: Mar 16 Transplant: Apr 20 🍅 Harvest: Jun 15 – Aug 10

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 355 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Peas needs ~1,094 GDD — county provides 3,447 GDD Excellent fit

Peas Planting Timeline โ€” Hamilton County, IL

Peas Planting Calendar

Activity When Date Range
Start Indoors March 5 Mar 5 โ€“ Mar 19
Transplant Outdoors April 9 Apr 9 โ€“ Apr 23
Direct Sow March 26 Mar 26 โ€“ Apr 16
Fall Sowing August 14 Aug 14 โ€“ Aug 28
Harvest June 4 Jun 4 โ€“ Jul 30

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

55โ€“70 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 6a

Growing Season

197 days

Growing Tips for Hamilton County

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

Level Up Your Garden

๐ŸŒพ 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 35ยฐF, under 45% humidity.

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

Frequently Asked Questions

When should I plant Peas in Hamilton County, IL?

Hamilton County is in Zone 6a with an average last frost of April 9. Plan your Peas planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Hamilton County, IL?

Hamilton County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 9 and first fall frost is October 23.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Hamilton County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Hamilton County, IL. Local conditions may vary. Last updated: April 2026.