When to Plant Lima Beans in DeKalb County, IL
May to-do list for DeKalb County, Illinois
A quick May briefing for DeKalb County, Illinois gardeners — what's urgent, what's next, and what can wait.
Lima beans are a warm-season legume producing large, creamy beans with a buttery texture. Both bush and pole varieties are available, with pole types yielding more.
DeKalb County, Illinois is in USDA Zone 5b. The average last spring frost is April 22 and the first fall frost is October 16, giving you a growing season of approximately 177 days.
At an elevation of 1,332 feet, DeKalb County receives approximately 34.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Lima Beans during the growing season.
DeKalb County Soil Profile
Soil Type
Silt Loam
Soil pH
6.2-7.2
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 DeKalb County
How your county's soil matches Lima Beans's growing requirements.
Soil pH
Your soil pH (6.2–7.2) overlaps with Lima Beans's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in DeKalb County is excellent for Lima Beans — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Lima Beans.
Organic Matter
Organic matter is excellent (5.1%) — Lima Beans will thrive.
How to Plant Lima Beans
Succession Planting Lima Beans
Sow every 6.9 weeks. Last sowing by Jul 18 to harvest before frost.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Lima Beans
Lima Beans needs approximately 0.9 inches of water per week (3.9" per month). Here's how your county's rainfall compares month by month.
| Month | Lima Beans Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 2.2" | 0" | ❄️ Dormant |
| Apr | 3.9" | 3.1" | 0.8" | 💧 Light watering |
| May | 3.9" | 3.7" | 0.2" | 💧 Light watering |
| Jun | 3.9" | 4.4" | 0" | ✅ Rainfall sufficient |
| Jul | 3.9" | 3.9" | 0" | ✅ Rainfall sufficient |
| Aug | 3.9" | 4.1" | 0" | ✅ Rainfall sufficient |
| Sep | 3.9" | 3.1" | 0.8" | 💧 Light watering |
| Oct | 3.9" | 2.6" | 1.3" | 💧 Light watering |
| Nov | — | 2.6" | 0" | ❄️ Dormant |
| Dec | — | 1.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in DeKalb County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Lima Beans 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.
Lima Beans Planting Timeline — DeKalb County, IL
Lima Beans Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | April 29 | Apr 29 – May 20 |
| Harvest | July 1 | Jul 1 – Aug 12 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Direct Sow |
| May | Direct Sow |
| June | — |
| July | Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.9"/week · 1-2 times/week
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 5b
📆 Growing Season
177 days in DeKalb County
Growing Tips for Lima Beans in DeKalb County
Direct sow Lima Beans outdoors after April 22 in DeKalb County when soil has warmed and frost danger has passed.
Common pests for Lima Beans in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.
General growing tips
Direct sow after soil is thoroughly warm at 65F or above. Do not soak seeds before planting as they may crack. Harvest when pods are plump but still green for fresh limas.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Lima Beans in Other Locations
Frequently Asked Questions
When should I plant Lima Beans in DeKalb County, IL?
DeKalb County is in Zone 5b with an average last frost of April 22. Plan your Lima Beans planting based on this frost date — see the calendar above for exact timing.
What planting zone is DeKalb County, IL?
DeKalb County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 22 and first fall frost is October 16.
Your DeKalb County Garden Planner — Free
A 24-page printable planner built for DeKalb 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.