Blog

When to Plant Valerian in Washington County, UT

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.

Washington County, Utah is in USDA Zone 8a. The average last spring frost is April 6 and the first fall frost is November 1, giving you a growing season of approximately 209 days.

At an elevation of 3,524 feet, Washington County receives approximately 12.7 inches of rainfall annually with predominantly loam soil. Summer highs average 90ยฐF, providing good warmth for Valerian during the growing season. With low rainfall, drip irrigation is essential for growing Valerian successfully. Mulch heavily to conserve soil moisture.

Washington County, UT (Zone 8a) Long season
209 days
Last Spring Frost April 6
209 growing days
First Fall Frost November 1

Washington County Soil Profile

Soil Type

Loam

Soil pH

6.7-8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Mar 20 🍅 Harvest: Jul 24 – Oct 30
Recommended (50%) ✗ May not fit
Transplant: Apr 13 🍅 Harvest: Aug 17 – Nov 23
Safe Start (90%) ✓ Fits season (312 days to spare)
Transplant: Jun 3 🍅 Harvest: Oct 7 – Jan 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
1.0″/week
Rainfall provides
0.3″/week
You supply
1.3″/week
Watering frequency 2-3 times/week
Season total 2,332 gal / 100 sq ft
Drought risk

Water stress score is 10/10 โ€” consider drought-tolerant varieties and mulching

Valerian needs ~2,625 GDD — county provides 3,657 GDD Excellent fit

Valerian Planting Timeline โ€” Washington County, UT

Valerian Planting Calendar

Activity When Date Range
Transplant Outdoors April 13 Apr 13 โ€“ Apr 27
Harvest August 17 Aug 17 โ€“ Nov 23

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Transplant Outdoors
May โ€”
June โ€”
July โ€”
August Harvest
September Harvest
October Harvest
November Harvest
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 8a

Growing Season

209 days

Growing Tips for Washington 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 Washington County, UT?

Washington County is in Zone 8a with an average last frost of April 6. Plan your Valerian planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Washington County, UT?

Washington County, Utah is in USDA Hardiness Zone 8a. The average last spring frost is April 6 and first fall frost is November 1.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Washington County gardeners in Zone 8a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

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 Washington County, UT. Local conditions may vary. Last updated: April 2026.