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When to Plant Valerian in Warren County, IN

Warren County, Indiana Zone 6a May

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Avg. last frost April 19
Avg. first frost October 14
Soil temp (4") 59°F
Watering Low
Pest pressure Low
Daylight 14.2 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.

Warren County, Indiana is in USDA Zone 6a. The average last spring frost is April 19 and the first fall frost is October 14, giving you a growing season of approximately 178 days.

At an elevation of 764 feet, Warren County receives approximately 40.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Valerian during the growing season.

Warren County, IN (Zone 6a) Moderate season
178 days
Last Spring Frost April 19
178 growing days
First Fall Frost October 14
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Warren County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Apr 21 🍅 Harvest: Aug 25 – Nov 3
Recommended (50%) ✗ May not fit
Transplant: Apr 26 🍅 Harvest: Aug 30 – Nov 8
Safe Start (90%) ✗ May not fit
Transplant: May 12 🍅 Harvest: Sep 15 – Nov 24

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 Warren County

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

Soil pH

Your soil pH (5.9–7.1) overlaps with Valerian's range (5.5–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Warren 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
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 55 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 1.5" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.8" 0" ❄️ Dormant
Apr 4.3" 3.7" 0.6" 💧 Light watering
May 4.3" 4.7" 0" ✅ Rainfall sufficient
Jun 4.3" 5.4" 0" ✅ Rainfall sufficient
Jul 4.3" 4.7" 0" ✅ Rainfall sufficient
Aug 4.3" 4.6" 0" ✅ Rainfall sufficient
Sep 4.3" 3.7" 0.6" 💧 Light watering
Oct 4.3" 3.1" 1.2" 💧 Light watering
Nov 2.7" 0" ❄️ Dormant
Dec 2.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Warren 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 2,581 GDD Good fit

Valerian Planting Timeline — Warren County, IN

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
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Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

120–180 days

🧪 Soil pH

Needs 5.5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

178 days in Warren County

Growing Tips for Valerian in Warren County

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

Your 178.0-day growing season in Warren 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 Warren County, IN?

Warren County is in Zone 6a 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 Warren County, IN?

Warren County, Indiana is in USDA Hardiness Zone 6a. The average last spring frost is April 19 and first fall frost is October 14.

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Your Warren County Garden Planner — Free

A 24-page printable planner built for Warren County (Zone 6a). 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 Warren County, IN. 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.