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When to Plant Yarrow in Grant County, WI

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.

Grant County, Wisconsin is in USDA Zone 4b. The average last spring frost is April 28 and the first fall frost is October 8, giving you a growing season of approximately 163 days.

At an elevation of 884 feet, Grant County receives approximately 37.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81ยฐF, so choose short-season varieties of Yarrow to ensure they mature before fall.

Grant County, WI (Zone 4b) Moderate season
163 days
Last Spring Frost April 28
163 growing days
First Fall Frost October 8

Grant County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (9 days to spare)
Transplant: Apr 30 🍅 Harvest: Jul 30 – Sep 24
Recommended (50%) ✓ Fits season (9 days to spare)
Transplant: May 5 🍅 Harvest: Aug 4 – Sep 29
Safe Start (90%) ✓ Fits season (3 days to spare)
Transplant: May 22 🍅 Harvest: Aug 21 – Oct 16

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
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Yarrow needs ~1,129 GDD — county provides 1,752 GDD Excellent fit

Yarrow Planting Timeline โ€” Grant County, WI

Yarrow Planting Calendar

Activity When Date Range
Transplant Outdoors May 5 May 5 โ€“ May 19
Harvest August 4 Aug 4 โ€“ Sep 29

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 โ€”
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

163 days

Growing Tips for Grant 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 Grant County, WI?

Grant County is in Zone 4b with an average last frost of April 28. Plan your Yarrow planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Grant County, WI?

Grant County, Wisconsin is in USDA Hardiness Zone 4b. The average last spring frost is April 28 and first fall frost is October 8.

๐ŸŒฑ

Plan Your Garden with Confidence

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