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When to Plant Valerian in Grand County, UT

Grand County, Utah Zone 6b May

Your May gardening checklist

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Grand County, Utah.

Avg. last frost April 19
Avg. first frost October 13
Soil temp (4") 49°F
Watering Moderate
Pest pressure Low
Daylight 14.1 hrs

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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.

Grand County, Utah is in USDA Zone 6b. The average last spring frost is April 19 and the first fall frost is October 13, giving you a growing season of approximately 177 days.

At an elevation of 5,415 feet, Grand County receives approximately 23.1 inches of rainfall annually with predominantly loam soil. Summer highs average 91°F, providing good warmth for Valerian during the growing season.

Grand County, UT (Zone 6b) Moderate season
177 days
Last Spring Frost April 19
177 growing days
First Fall Frost October 13

Grand County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Apr 20 🍅 Harvest: Aug 24 – Nov 2
Recommended (50%) ✗ May not fit
Transplant: Apr 26 🍅 Harvest: Aug 30 – Nov 8
Safe Start (90%) ✗ May not fit
Transplant: May 14 🍅 Harvest: Sep 17 – Nov 26

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.

Soil Compatibility in Grand County

How your county's soil matches Valerian's growing requirements.

Soil pH

Your soil pH (6.4–7.9) is more alkaline than Valerian prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Grand County is excellent for Valerian — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Valerian.

Organic Matter

Organic matter is moderate (2.1%). Annual compost additions will help Valerian.

How to Plant Valerian

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.9″/week
Watering frequency 2-3 times/week
Season total 1,421 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Valerian

Valerian needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Valerian Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 4.3" 2.2" 2.1" 💧 Light watering
May 4.3" 2.9" 1.4" 💧 Light watering
Jun 4.3" 1.5" 2.8" 🚿 Regular watering
Jul 4.3" 2.4" 1.9" 💧 Light watering
Aug 4.3" 2.1" 2.2" 🚿 Regular watering
Sep 4.3" 1.8" 2.5" 🚿 Regular watering
Oct 4.3" 2.1" 2.2" 🚿 Regular watering
Nov 1.6" 0" ❄️ Dormant
Dec 1.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Grand County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Valerian Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Valerian needs ~2,738 GDD — county provides 3,230 GDD Good fit

Valerian Planting Timeline — Grand County, UT

Valerian Planting Calendar

Activity When Date Range
Transplant Outdoors April 26 Apr 26 – May 10
Harvest August 30 Aug 30 – Nov 8

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Transplant Outdoors
May Transplant Outdoors
June
July
August Harvest
September Harvest
October Harvest
November Harvest
December

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

120–180 days

🧪 Soil pH

Needs 5.5–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6b

📆 Growing Season

177 days in Grand County

Growing Tips for Valerian in Grand County

Direct sow Valerian outdoors after April 19 in Grand County when soil has warmed and frost danger has passed.

Your 177.0-day growing season in Grand County is tight for Valerian (120.0-180.0 days to maturity). Start indoors and choose early-maturing varieties.

Grand County receives only 23" of rain annually. Valerian needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Valerian in Grand County, UT?

Grand County is in Zone 6b with an average last frost of April 19. Plan your Valerian planting based on this frost date — see the calendar above for exact timing.

What planting zone is Grand County, UT?

Grand County, Utah is in USDA Hardiness Zone 6b. The average last spring frost is April 19 and first fall frost is October 13.

🌱

Your Grand County Garden Planner — Free

A 24-page printable planner built for Grand County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Grand County, UT. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.