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When to Plant Scarlet Runner Beans in Palo Alto 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.

Palo Alto County, Iowa is in USDA Zone 4b. The average last spring frost is April 27 and the first fall frost is October 8, giving you a growing season of approximately 164 days.

At an elevation of 1,358 feet, Palo Alto County receives approximately 34.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81ยฐF, so choose short-season varieties of Scarlet Runner Beans to ensure they mature before fall.

Palo Alto County, IA (Zone 4b) Moderate season
164 days
Last Spring Frost April 27
164 growing days
First Fall Frost October 8

Palo Alto County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (46 days to spare)
Start indoors: Feb 17 Transplant: May 12 🍅 Harvest: Jul 14 – Aug 18
Recommended (50%) ✓ Fits season (45 days to spare)
Start indoors: Feb 23 Transplant: May 18 🍅 Harvest: Jul 20 – Aug 24
Safe Start (90%) ✓ Fits season (46 days to spare)
Start indoors: Mar 12 Transplant: Jun 4 🍅 Harvest: Aug 6 – Sep 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
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 195 gal / 100 sq ft
Drought risk

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

Scarlet Runner Beans needs ~752 GDD — county provides 1,763 GDD Excellent fit

Scarlet Runner Beans Planting Timeline โ€” Palo Alto County, IA

Scarlet Runner Beans Planting Calendar

Activity When Date Range
Start Indoors February 23 Feb 23 โ€“ Mar 9
Transplant Outdoors May 18 May 18 โ€“ Jun 1
Direct Sow May 11 May 11 โ€“ Jun 1
Harvest July 20 Jul 20 โ€“ Aug 24

Plant 1" deep ยท 15" apart ยท Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

60โ€“80 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 4b

Growing Season

164 days

Growing Tips for Palo Alto County

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

Avoid Planting Near

  • Onion
  • Garlic

Level Up Your Garden

Frequently Asked Questions

When should I plant Scarlet Runner Beans in Palo Alto County, IA?

Palo Alto County is in Zone 4b with an average last frost of April 27. Plan your Scarlet Runner Beans planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Palo Alto County, IA?

Palo Alto County, Iowa is in USDA Hardiness Zone 4b. The average last spring frost is April 27 and first fall frost is October 8.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Palo Alto County gardeners in Zone 4b organize planting dates, track what's growing, and never miss a planting window.

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