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When to Plant Valerian in Stephens County, OK

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.

Stephens County, Oklahoma is in USDA Zone 7b. 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 979 feet, Stephens County receives approximately 26.1 inches of rainfall annually with predominantly loam soil. Summer highs average 90ยฐF, providing good warmth for Valerian during the growing season.

Stephens County, OK (Zone 7b) Long season
209 days
Last Spring Frost April 6
209 growing days
First Fall Frost November 1

Stephens County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Apr 4 🍅 Harvest: Aug 8 – Nov 14
Recommended (50%) ✗ May not fit
Transplant: Apr 13 🍅 Harvest: Aug 17 – Nov 23
Safe Start (90%) ✗ May not fit
Transplant: Apr 22 🍅 Harvest: Aug 26 – Dec 2

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 Stephens County

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

Soil pH

Your soil pH (6.3โ€“7.6) overlaps with Valerian's range (5.5โ€“7.0), though not a perfect match.

Soil Texture

The loam soil in Stephens County is excellent for Valerian โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.3%) โ€” 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
0.5″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 1,061 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” 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 โ€” 0.6" 0" โ„๏ธ Dormant
Feb โ€” 1" 0" โ„๏ธ Dormant
Mar โ€” 1.6" 0" โ„๏ธ Dormant
Apr 4.3" 2.7" 1.6" ๐Ÿ’ง Light watering
May 4.3" 3.9" 0.4" ๐Ÿ’ง Light watering
Jun 4.3" 4.3" 0" โœ… Rainfall sufficient
Jul 4.3" 3" 1.3" ๐Ÿ’ง Light watering
Aug 4.3" 3.5" 0.8" ๐Ÿ’ง Light watering
Sep 4.3" 2.4" 1.9" ๐Ÿ’ง Light watering
Oct 4.3" 1.9" 2.4" ๐Ÿšฟ Regular watering
Nov 4.3" 0.8" 3.5" ๐Ÿšฟ Regular watering
Dec โ€” 0.6" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Nov in Stephens County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 3,657 GDD Excellent fit

Valerian Planting Timeline โ€” Stephens County, OK

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

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

1"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

120โ€“180 days

๐Ÿงช Soil pH

Needs 5.5โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 7b

๐Ÿ“† Growing Season

209 days in Stephens County

Growing Tips for Valerian in Stephens County

Direct sow Valerian outdoors after April 06 in Stephens 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 Stephens County, OK?

Stephens County is in Zone 7b 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 Stephens County, OK?

Stephens County, Oklahoma is in USDA Hardiness Zone 7b. 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 Stephens County gardeners in Zone 7b 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 Stephens County, OK. Local conditions may vary. Last updated: April 2026.