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When to Plant Valerian in Clatsop County, OR

Clatsop County, Oregon Zone 9a May

May to-do list for Clatsop County, Oregon

Here's what deserves your attention in Clatsop County, Oregon this month. Everything below is tailored to Zone 9a and timed around your local frost dates.

Avg. last frost April 12
Avg. first frost November 4
Soil temp (4") 72°F
Watering Moderate
Pest pressure High
Daylight 14.8 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.

Clatsop County, Oregon is in USDA Zone 9a. The average last spring frost is April 12 and the first fall frost is November 4, giving you a growing season of approximately 206 days.

At an elevation of 412 feet, Clatsop County receives approximately 54.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Valerian during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Valerian root diseases.

Clatsop County, OR (Zone 9a) Long season
206 days
Last Spring Frost April 12
206 growing days
First Fall Frost November 4
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Clatsop County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Apr 8 🍅 Harvest: Aug 12 – Nov 18
Recommended (50%) ✗ May not fit
Transplant: Apr 19 🍅 Harvest: Aug 23 – Nov 29
Safe Start (90%) ✗ May not fit
Transplant: May 7 🍅 Harvest: Sep 10 – Dec 17

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 Clatsop County

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

Soil pH

Your soil pH (5.6–6.7) is within Valerian's preferred range (5.5–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.9%) — Valerian will thrive.

How to Plant Valerian

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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 8.4" 0" ❄️ Dormant
Feb 5.2" 0" ❄️ Dormant
Mar 4.8" 0" ❄️ Dormant
Apr 4.3" 3.8" 0.5" 💧 Light watering
May 4.3" 3.6" 0.7" 💧 Light watering
Jun 4.3" 2.1" 2.2" 🚿 Regular watering
Jul 4.3" 0.9" 3.4" 🚿 Regular watering
Aug 4.3" 1.1" 3.2" 🚿 Regular watering
Sep 4.3" 2.4" 1.9" 💧 Light watering
Oct 4.3" 4.2" 0.1" 💧 Light watering
Nov 4.3" 8.4" 0" ✅ Rainfall sufficient
Dec 9.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Clatsop 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 ~2,175 GDD — county provides 2,987 GDD Excellent fit

Valerian Planting Timeline — Clatsop County, OR

Valerian Planting Calendar

Activity When Date Range
Transplant Outdoors April 19 Apr 19 – May 3
Harvest August 23 Aug 23 – Nov 29

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
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Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

120–180 days

🧪 Soil pH

Needs 5.5–7 · Your soil: ideal

🗺️ USDA Zone

Zone 9a

📆 Growing Season

206 days in Clatsop County

Growing Tips for Valerian in Clatsop County

Direct sow Valerian outdoors after April 12 in Clatsop County when soil has warmed and frost danger has passed.

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 Clatsop County, OR?

Clatsop County is in Zone 9a with an average last frost of April 12. Plan your Valerian planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clatsop County, OR?

Clatsop County, Oregon is in USDA Hardiness Zone 9a. The average last spring frost is April 12 and first fall frost is November 4.

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Your Clatsop County Garden Planner — Free

A 24-page printable planner built for Clatsop County (Zone 9a). 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 Clatsop County, OR. 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.