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When to Plant Valerian in Florence County, WI

Valerian is a tall perennial herb with fragrant white or pink flower clusters, valued for its root which is used as a natural sleep aid. It attracts pollinators and earthworms.

Florence County, Wisconsin is in USDA Zone 4a. The average last spring frost is May 26 and the first fall frost is September 21, giving you a growing season of approximately 118 days.

At an elevation of 1,147 feet, Florence County receives approximately 34.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 82ยฐF, so choose short-season varieties of Valerian to ensure they mature before fall.

Florence County, WI (Zone 4a) Short season
118 days
Last Spring Frost May 26
118 growing days
First Fall Frost September 21

Florence County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 27 🍅 Harvest: Sep 30 – Oct 21
Recommended (50%) ✗ May not fit
Transplant: Jun 2 🍅 Harvest: Oct 6 – Oct 27
Safe Start (90%) ✗ May not fit
Transplant: Jun 18 🍅 Harvest: Oct 22 – Nov 12

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
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Valerian needs ~1,725 GDD — county provides 1,357 GDD May not mature

Valerian Planting Timeline โ€” Florence County, WI

Valerian Planting Calendar

Activity When Date Range
Transplant Outdoors June 2 Jun 2 โ€“ Jun 16
Harvest October 6 Oct 6 โ€“ Oct 27

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 โ€”
June Transplant Outdoors
July โ€”
August โ€”
September โ€”
October Harvest
November โ€”
December โ€”

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate โ€” regular watering

Days to Maturity

120โ€“180 days

Soil pH

5.5 โ€“ 7

USDA Zone

Zone 4a

Growing Season

118 days

Growing Tips for Florence County

Start seeds indoors and transplant after last frost. Harvest roots in fall of the second year. Deadhead flowers unless you want self-seeding. Cats are attracted to valerian root.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Valerian in Florence County, WI?

Florence County is in Zone 4a with an average last frost of May 26. Plan your Valerian planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Florence County, WI?

Florence County, Wisconsin is in USDA Hardiness Zone 4a. The average last spring frost is May 26 and first fall frost is September 21.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Florence County gardeners in Zone 4a 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 Florence County, WI. Local conditions may vary. Last updated: April 2026.