When to Plant Peas in Putnam 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.
Putnam County, Illinois is in USDA Zone 5a. 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 Peas during the growing season.
Putnam County Soil Profile
Soil Type
Silt Loam
Soil pH
6-6.7
Drainage
Well Drained
Plant Planting Risk Windows
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 Putnam County
How your county's soil matches Peas's growing requirements.
Soil pH
Your soil pH (6.0–6.7) is within Peas's preferred range (6.0–7.5).
Soil Texture
The silt loam soil in Putnam 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 (4.3%) — Peas will thrive.
How to Plant Peas
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Peas
Sow every 6.3 weeks. Last sowing by Aug 04 to harvest before frost.
For a dedicated fall crop, sow by Aug 04.
Plant Water Budget
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 | — | 1.8" | 0" | ❄️ Dormant |
| Feb | — | 2" | 0" | ❄️ Dormant |
| Mar | — | 3.1" | 0" | ❄️ Dormant |
| Apr | 3" | 3.6" | 0" | ✅ Rainfall sufficient |
| May | 3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jun | 3" | 5.2" | 0" | ✅ Rainfall sufficient |
| Jul | 3" | 5" | 0" | ✅ Rainfall sufficient |
| Aug | 3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Sep | 3" | 3.3" | 0" | ✅ Rainfall sufficient |
| Oct | 3" | 3.3" | 0" | ✅ Rainfall sufficient |
| 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.
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 Planting Timeline — Putnam County, IL
Peas Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 17 | Mar 17 – Mar 31 |
| Transplant Outdoors | April 21 | Apr 21 – May 5 |
| Direct Sow | April 7 | Apr 7 – Apr 28 |
| Harvest | June 16 | Jun 16 – Aug 11 |
| Fall Sowing | August 4 | Aug 4 – Aug 18 |
Plant 1" deep · 4" apart · Rows 18" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Transplant Outdoors Direct Sow |
| May | Transplant Outdoors |
| June | Harvest |
| July | 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: ideal
🗺️ USDA Zone
Zone 5a
📆 Growing Season
175 days in Putnam County
Growing Tips for Peas in Putnam County
Direct sow Peas outdoors after April 21 in Putnam 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 Putnam County
Heat-tolerant peas — plant very early or as fall crop
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Very easy to save. Self-pollinating means varieties stay true.
Peas in Other Locations
Frequently Asked Questions
When should I plant Peas in Putnam County, IL?
Putnam County is in Zone 5a with an average last frost of April 21. Plan your Peas 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 5a. The average last spring frost is April 21 and first fall frost is October 13.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Putnam County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.
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