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When to Plant Yarrow in Herkimer County, NY

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.

Herkimer County, New York is in USDA Zone 4b. The average last spring frost is May 15 and the first fall frost is September 30, giving you a growing season of approximately 138 days.

At an elevation of 160 feet, Herkimer County receives approximately 48.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 82ยฐF, so choose short-season varieties of Yarrow to ensure they mature before fall.

Herkimer County, NY (Zone 4b) Short season
138 days
Last Spring Frost May 15
138 growing days
First Fall Frost September 30

Herkimer County Soil Profile

Soil Type

Silt Loam

Soil pH

5.1-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 18 🍅 Harvest: Aug 17 – Oct 12
Recommended (50%) ✗ May not fit
Transplant: May 22 🍅 Harvest: Aug 21 – Oct 16
Safe Start (90%) ✗ May not fit
Transplant: Jun 7 🍅 Harvest: Sep 6 – Nov 1

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
1.5″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Yarrow needs ~1,208 GDD — county provides 1,587 GDD Excellent fit

Yarrow Planting Timeline โ€” Herkimer County, NY

Yarrow Planting Calendar

Activity When Date Range
Transplant Outdoors May 22 May 22 โ€“ Jun 5
Harvest August 21 Aug 21 โ€“ Oct 16

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 Transplant Outdoors
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 4b

Growing Season

138 days

Growing Tips for Herkimer 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 Herkimer County, NY?

Herkimer County is in Zone 4b with an average last frost of May 15. Plan your Yarrow planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Herkimer County, NY?

Herkimer County, New York is in USDA Hardiness Zone 4b. The average last spring frost is May 15 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 Herkimer 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 Herkimer County, NY. Local conditions may vary. Last updated: April 2026.