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When to Plant Valerian in Josephine County, OR

Josephine County, Oregon Zone 8b May

Your May gardening checklist

Your Josephine County, Oregon garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost April 22
Avg. first frost October 20
Soil temp (4") 69°F
Watering High
Pest pressure High
Daylight 14.4 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.

Josephine County, Oregon is in USDA Zone 8b. The average last spring frost is April 22 and the first fall frost is October 20, giving you a growing season of approximately 181 days.

At an elevation of 340 feet, Josephine County receives approximately 52.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°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.

Josephine County, OR (Zone 8b) Moderate season
181 days
Last Spring Frost April 22
181 growing days
First Fall Frost October 20

Josephine County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Apr 16 🍅 Harvest: Aug 20 – Nov 26
Recommended (50%) ✗ May not fit
Transplant: Apr 29 🍅 Harvest: Sep 2 – Dec 9
Safe Start (90%) ✗ May not fit
Transplant: May 19 🍅 Harvest: Sep 22 – Dec 29

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 Josephine County

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

Soil pH

Your soil pH (5.7–6.2) is within Valerian's preferred range (5.5–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.4%) — 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
1.2″/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 6.6" 0" ❄️ Dormant
Mar 6.2" 0" ❄️ Dormant
Apr 4.3" 3.6" 0.7" 💧 Light watering
May 4.3" 2.7" 1.6" 💧 Light watering
Jun 4.3" 2" 2.3" 🚿 Regular watering
Jul 4.3" 0.8" 3.5" 🚿 Regular watering
Aug 4.3" 0.9" 3.4" 🚿 Regular watering
Sep 4.3" 1.9" 2.4" 🚿 Regular watering
Oct 4.3" 4.4" 0" ✅ Rainfall sufficient
Nov 7.4" 0" ❄️ Dormant
Dec 8.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Josephine 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 ~2,625 GDD — county provides 3,167 GDD Good fit

Valerian Planting Timeline — Josephine County, OR

Valerian Planting Calendar

Activity When Date Range
Transplant Outdoors April 29 Apr 29 – May 13
Harvest September 2 Sep 2 – Dec 9

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
September Harvest
October Harvest
November Harvest
December Harvest

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 8b

📆 Growing Season

181 days in Josephine County

Growing Tips for Valerian in Josephine County

Direct sow Valerian outdoors after April 22 in Josephine County when soil has warmed and frost danger has passed.

Your 181.0-day growing season in Josephine County is tight for Valerian (120.0-180.0 days to maturity). Start indoors and choose early-maturing varieties.

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 Josephine County, OR?

Josephine County is in Zone 8b with an average last frost of April 22. Plan your Valerian planting based on this frost date — see the calendar above for exact timing.

What planting zone is Josephine County, OR?

Josephine County, Oregon is in USDA Hardiness Zone 8b. The average last spring frost is April 22 and first fall frost is October 20.

🌱

Your Josephine County Garden Planner — Free

A 24-page printable planner built for Josephine County (Zone 8b). 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 Josephine 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.