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When to plant Valerian in New Castle County, DE

Plant Valerian in New Castle County, between April 13 and April 27 — the only viable window. Zone 7b's short season (208 frost-free days) rules out a fall crop.

When to Plant Valerian in New Castle County, DE

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.

New Castle County, Delaware is in USDA Zone 7b. The average last spring frost is April 6 and the first fall frost is October 31, giving you a growing season of approximately 208 days.

At an elevation of 415 feet, New Castle County receives approximately 38.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Valerian during the growing season.

New Castle County, DE (Zone 7b) Long season
208 days
Last Spring Frost April 6
208 growing days
First Fall Frost October 31

New Castle County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-7.1

Drainage

Well Drained

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 2.4" 0" ❄️ Dormant
Feb 2.7" 0" ❄️ Dormant
Mar 3.4" 0" ❄️ Dormant
Apr 4.3" 3.2" 1.1" 💧 Light watering
May 4.3" 3.3" 1" 💧 Light watering
Jun 4.3" 3.3" 1" 💧 Light watering
Jul 4.3" 4.1" 0.2" 💧 Light watering
Aug 4.3" 3.2" 1.1" 💧 Light watering
Sep 4.3" 3.1" 1.2" 💧 Light watering
Oct 4.3" 3.2" 1.1" 💧 Light watering
Nov 3.4" 0" ❄️ Dormant
Dec 2.9" 0" ❄️ Dormant

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

Valerian Planting Timeline — New Castle County, DE

Valerian Planting Calendar

Activity When Date Range
Transplant Outdoors April 13 Apr 13 – Apr 27
Harvest August 17 Aug 17 – Nov 23

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

120–180 days

🧪 Soil pH

Needs 5.5–7 · Your soil: N/A

🗺️ USDA Zone

Zone 7b

📆 Growing Season

208 days in New Castle County

Growing Tips for New Castle County

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 New Castle County, DE?

New Castle County is in Zone 7b with an average last frost of April 6. Plan your Valerian planting based on this frost date — see the calendar above for exact timing.

What planting zone is New Castle County, DE?

New Castle County, Delaware is in USDA Hardiness Zone 7b. The average last spring frost is April 6 and first fall frost is October 31.

When should I plant Valerian in New Castle County, DE?

In New Castle County, DE, plant Valerian after the last frost (around April 6) and before the first frost (around October 31). Best results when soil holds above 50°F.

What growing zone is New Castle County, DE for Valerian?

New Castle County sits in USDA Zone 7b. Valerian grows reliably in zones 3a through 9b, so it's a good fit here.

Can Valerian grow in New Castle County's climate?

Yes — Valerian grows well in New Castle County's temperate climate. New Castle County averages a 208-day frost-free season, with last frost around April 6 and first frost around October 31.

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Your New Castle County Garden Planner — Free

A 22-page printable planner built for New Castle County (Zone 7b). 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 New Castle County, DE. Local conditions may vary. Last updated: July 2026.

Sources & credits

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