When to Plant Green Beans in Plymouth County, IA
Your May planting checklist for Plymouth County, Iowa
We've pulled the most time-sensitive tasks for Plymouth County, Iowa this May and put them front and centre. Tackle them in order.
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Put green beans seeds straight in the ground
Keep the top inch of soil moist until germination — a gentle morning watering for 5–7 days does the job.
Green beans are a warm-season staple available as bush or pole types. Bush beans produce a concentrated harvest while pole beans provide a longer picking season.
Plymouth County, Iowa is in USDA Zone 5a. The average last spring frost is April 30 and the first fall frost is October 6, giving you a growing season of approximately 159 days.
At an elevation of 1,392 feet, Plymouth County receives approximately 38 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Green Beans to ensure they mature before fall.
Plymouth County Soil Profile
Soil Type
Silt Loam
Soil pH
6-7.2
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 Plymouth County
How your county's soil matches Green Beans's growing requirements.
Soil pH
Your soil pH (6.0–7.2) overlaps with Green Beans's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Plymouth County is excellent for Green Beans — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.7%) — Green Beans will thrive.
How to Plant Green Beans
Succession Planting Green Beans
Sow every 5.7 weeks. Last sowing by Aug 02 to harvest before frost.
Plant Water Budget
Monthly Watering Guide for Green Beans
Green 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 | Green Beans Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 2.6" | 0" | ❄️ Dormant |
| Apr | 3.9" | 3.9" | 0" | ✅ Rainfall sufficient |
| May | 3.9" | 4.8" | 0" | ✅ Rainfall sufficient |
| Jun | 3.9" | 4.2" | 0" | ✅ Rainfall sufficient |
| Jul | 3.9" | 4.4" | 0" | ✅ Rainfall sufficient |
| Aug | 3.9" | 4.3" | 0" | ✅ Rainfall sufficient |
| Sep | 3.9" | 3.4" | 0.5" | 💧 Light watering |
| Oct | 3.9" | 2.7" | 1.2" | 💧 Light watering |
| Nov | — | 2.8" | 0" | ❄️ Dormant |
| Dec | — | 1.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Plymouth County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Green 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.
Green Beans Planting Timeline — Plymouth County, IA
Green Beans Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | May 7 | May 7 – May 28 |
| Harvest | July 2 | Jul 2 – Aug 27 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Direct Sow |
| June | — |
| July | Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.9"/week · Natural rainfall sufficient
📅 Days to Maturity
50–65 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 5a
📆 Growing Season
159 days in Plymouth County
Growing Tips for Green Beans in Plymouth County
Direct sow Green Beans outdoors after April 30 in Plymouth County when soil has warmed and frost danger has passed.
Common pests for Green 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 last frost when soil is warm. Provide sturdy supports for pole varieties. Pick beans regularly when young and tender to encourage continued production.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Avoid harvesting during damp weather. Isolate 25 ft between varieties.
Green Beans in Other Locations
Frequently Asked Questions
When should I plant Green Beans in Plymouth County, IA?
Plymouth County is in Zone 5a with an average last frost of April 30. Plan your Green Beans planting based on this frost date — see the calendar above for exact timing.
What planting zone is Plymouth County, IA?
Plymouth County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 30 and first fall frost is October 6.
Your Plymouth County Garden Planner — Free
A 24-page printable planner built for Plymouth 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.