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When to Plant Yarrow in Mahoning County, OH

Yarrow is a drought-tolerant perennial herb with feathery foliage and flat-topped flower clusters in white, yellow, pink, or red. It attracts beneficial insects and is used in herbal medicine.

Mahoning County, Ohio is in USDA Zone 5b. The average last spring frost is April 30 and the first fall frost is October 18, giving you a growing season of approximately 171 days.

At an elevation of 759 feet, Mahoning County receives approximately 37.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Yarrow during the growing season.

Mahoning County, OH (Zone 5b) Moderate season
171 days
Last Spring Frost April 30
171 growing days
First Fall Frost October 18

Mahoning County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 3 🍅 Harvest: Aug 2 – Oct 18
Recommended (50%) ✗ May not fit
Transplant: May 7 🍅 Harvest: Aug 6 – Oct 22
Safe Start (90%) ✗ May not fit
Transplant: May 29 🍅 Harvest: Aug 28 – Nov 13

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
0.5″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Yarrow needs ~1,522 GDD — county provides 2,479 GDD Excellent fit

Yarrow Planting Timeline โ€” Mahoning County, OH

Yarrow Planting Calendar

Activity When Date Range
Transplant Outdoors May 7 May 7 โ€“ May 21
Harvest August 6 Aug 6 โ€“ Oct 22

Plant 0.5" deep ยท 8" apart ยท Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Low โ€” drought tolerant

Days to Maturity

90โ€“120 days

Soil pH

5.5 โ€“ 7

USDA Zone

Zone 5b

Growing Season

171 days

Growing Tips for Mahoning County

Direct sow or start from divisions. Yarrow thrives in poor soil and is very drought-tolerant. Deadhead to encourage reblooming. Divide clumps every 3 years.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Yarrow in Mahoning County, OH?

Mahoning County is in Zone 5b with an average last frost of April 30. Plan your Yarrow planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Mahoning County, OH?

Mahoning County, Ohio is in USDA Hardiness Zone 5b. The average last spring frost is April 30 and first fall frost is October 18.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Mahoning County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.

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Free download. Plan your entire garden season in minutes.

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