When to Plant Scarlet Runner Beans in Franklin County, IA
Scarlet runner beans are ornamental and edible climbing beans with vivid red flowers that attract hummingbirds. Both the young pods and mature beans are edible.
Franklin County, Iowa is in USDA Zone 4b. The average last spring frost is April 30 and the first fall frost is October 7, giving you a growing season of approximately 160 days.
At an elevation of 1,145 feet, Franklin County receives approximately 41.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Scarlet Runner Beans to ensure they mature before fall.
Franklin County Soil Profile
Soil Type
Silt Loam
Soil pH
6.2-7
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 Franklin County
How your county's soil matches Scarlet Runner Beans's growing requirements.
Soil pH
Your soil pH (6.2–7.0) is within Scarlet Runner Beans's preferred range (6.0–7.0).
Soil Texture
The silt loam soil in Franklin County is excellent for Scarlet Runner Beans — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.7%) — Scarlet Runner Beans will thrive.
How to Plant Scarlet Runner Beans
Succession Planting Scarlet Runner Beans
Sow every 6.9 weeks. Last sowing by Jul 19 to harvest before frost.
Plant Water Budget
Monthly Watering Guide for Scarlet Runner Beans
Scarlet Runner Beans needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Scarlet Runner Beans Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.9" | 0" | ❄️ Dormant |
| Feb | — | 2.1" | 0" | ❄️ Dormant |
| Mar | — | 2.8" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| May | 4.3" | 5.4" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 4.8" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Sep | 4.3" | 4" | 0.3" | 💧 Light watering |
| Oct | 4.3" | 3" | 1.3" | 💧 Light watering |
| Nov | — | 3.3" | 0" | ❄️ Dormant |
| Dec | — | 2.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Franklin County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Scarlet Runner 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.
Scarlet Runner Beans Planting Timeline — Franklin County, IA
Scarlet Runner Beans Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 26 | Feb 26 – Mar 12 |
| Transplant Outdoors | May 21 | May 21 – Jun 4 |
| Direct Sow | May 14 | May 14 – Jun 4 |
| Harvest | July 23 | Jul 23 – Aug 27 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors |
| April | — |
| May | Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Natural rainfall sufficient
📅 Days to Maturity
60–80 days
🧪 Soil pH
Needs 6–7 · Your soil: ideal
🗺️ USDA Zone
Zone 4b
📆 Growing Season
160 days in Franklin County
Growing Tips for Scarlet Runner Beans in Franklin County
Direct sow Scarlet Runner Beans outdoors after April 30 in Franklin County when soil has warmed and frost danger has passed.
Common pests for Scarlet Runner Beans in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.
General growing tips
Provide tall trellising for vigorous vines. Direct sow after frost. Harvest pods young for snap beans or let mature for shelling beans. Tubers are perennial in mild climates.
Companion Planting
Good Companions
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Scarlet Runner Beans in Other Locations
Frequently Asked Questions
When should I plant Scarlet Runner Beans in Franklin County, IA?
Franklin County is in Zone 4b with an average last frost of April 30. Plan your Scarlet Runner Beans planting based on this frost date — see the calendar above for exact timing.
What planting zone is Franklin County, IA?
Franklin County, Iowa is in USDA Hardiness Zone 4b. The average last spring frost is April 30 and first fall frost is October 7.
Plan Your Garden with Confidence
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