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When to Plant Valerian in Somerset County, ME

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.

Somerset County, Maine is in USDA Zone 4a. The average last spring frost is May 22 and the first fall frost is September 26, giving you a growing season of approximately 127 days.

At an elevation of 356 feet, Somerset County receives approximately 48.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80ยฐF, so choose short-season varieties of Valerian to ensure they mature before fall.

Somerset County, ME (Zone 4a) Short season
127 days
Last Spring Frost May 22
127 growing days
First Fall Frost September 26

Somerset County Soil Profile

Soil Type

Silt Loam

Soil pH

4.8-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 22 🍅 Harvest: Sep 25 – Oct 16
Recommended (50%) ✗ May not fit
Transplant: May 29 🍅 Harvest: Oct 2 – Oct 23
Safe Start (90%) ✗ May not fit
Transplant: Jun 10 🍅 Harvest: Oct 14 – Nov 4

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
1.6″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Valerian needs ~1,500 GDD — county provides 1,270 GDD May not mature

Valerian Planting Timeline โ€” Somerset County, ME

Valerian Planting Calendar

Activity When Date Range
Transplant Outdoors May 29 May 29 โ€“ Jun 12
Harvest October 2 Oct 2 โ€“ Oct 23

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 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

127 days

Growing Tips for Somerset 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 Somerset County, ME?

Somerset County is in Zone 4a with an average last frost of May 22. Plan your Valerian planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Somerset County, ME?

Somerset County, Maine is in USDA Hardiness Zone 4a. The average last spring frost is May 22 and first fall frost is September 26.

๐ŸŒฑ

Plan Your Garden with Confidence

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