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When to Plant Scarlet Runner Beans in Oscoda County, MI

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.

Oscoda County, Michigan is in USDA Zone 4b. The average last spring frost is May 20 and the first fall frost is September 30, giving you a growing season of approximately 133 days.

At an elevation of 765 feet, Oscoda County receives approximately 41 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Scarlet Runner Beans to ensure they mature before fall.

Oscoda County, MI (Zone 4b) Short season
133 days
Last Spring Frost May 20
133 growing days
First Fall Frost September 30

Oscoda County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (12 days to spare)
Start indoors: Mar 14 Transplant: Jun 6 🍅 Harvest: Aug 8 – Sep 12
Recommended (50%) ✓ Fits season (14 days to spare)
Start indoors: Mar 18 Transplant: Jun 10 🍅 Harvest: Aug 12 – Sep 16
Safe Start (90%) ✓ Fits season (16 days to spare)
Start indoors: Mar 31 Transplant: Jun 23 🍅 Harvest: Aug 25 – Sep 29

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
1.3″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Scarlet Runner Beans needs ~858 GDD — county provides 1,629 GDD Excellent fit

Scarlet Runner Beans Planting Timeline โ€” Oscoda County, MI

Scarlet Runner Beans Planting Calendar

Activity When Date Range
Start Indoors March 18 Mar 18 โ€“ Apr 1
Transplant Outdoors June 10 Jun 10 โ€“ Jun 24
Direct Sow June 3 Jun 3 โ€“ Jun 24
Harvest August 12 Aug 12 โ€“ Sep 16

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

Month-by-Month Timeline

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

133 days

Growing Tips for Oscoda 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 Oscoda County, MI?

Oscoda County is in Zone 4b with an average last frost of May 20. Plan your Scarlet Runner Beans planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Oscoda County, MI?

Oscoda County, Michigan is in USDA Hardiness Zone 4b. The average last spring frost is May 20 and first fall frost is September 30.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Oscoda 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 Oscoda County, MI. Local conditions may vary. Last updated: April 2026.