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When to Plant Valerian in USDA Zone 4a

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.

In Zone 4a, the average last spring frost is around May 6 and the first fall frost is around September 28, giving you a growing season of approximately 145 days.

Zone 4a Short season
145 days
Last Spring Frost May 6
145 growing days
First Fall Frost September 28

Valerian Planting Timeline — Zone 4a

Where Is USDA Zone 4a?

The map below highlights the states that contain Zone 4a. Click any state to see the Valerian planting schedule for that location.

Prints a clean, ink-friendly version without maps or navigation.

Valerian Planting Calendar — Zone 4a

Activity When Date Range
Transplant Outdoors May 13 May 13 – May 27
Harvest September 16 Sep 16 – Oct 7

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

Month-by-Month Timeline

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

Free Zone 4a Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 4a with start dates, transplant windows, and harvest times.

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Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate — regular watering

Days to Maturity

120–180 days

Soil pH

5.5 – 7

Zone Temperature Range

-30°F to -25°F average annual minimum

Growing Season

145 days (Zone 4a average)

Planting Specifications

Planting Depth0.5 inches
Plant Spacing8 inches apart
Row Spacing12 inches between rows

Growing Tips for Zone 4a

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

Level Up Your Garden

Saving Valerian Seeds

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Seedling Heat Mat $15-35

Warm soil for faster germination of heat-loving crops like tomatoes and peppers.

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Floating Row Covers $12-30

Protect plants from frost, wind, and pests while letting light and water through.

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Frequently Asked Questions

When should I plant Valerian in Zone 4a?

In Zone 4a, plan your Valerian planting around the average last frost date of May 6. Transplant seedlings around May 13.

Can Valerian grow in Zone 4a?

Yes, Valerian can grow well in Zone 4a, hardy in USDA zones 3a through 9b. Zone 4a has a growing season of approximately 145 days, which is sufficient for Valerian (120-180 days to maturity).

When can I harvest Valerian in Zone 4a?

In Zone 4a, expect to harvest Valerian from September 16 – October 7. Valerian takes 120-180 days from planting to harvest.

What is the last frost date for Zone 4a?

The average last spring frost in Zone 4a is around May 6, and the first fall frost is around September 28. This gives a growing season of approximately 145 days. These are 50% probability dates — actual frost dates vary year to year.

What should I plant next to Valerian?

Good companion plants for Valerian include Echinacea, Chamomile. These companions can help with pest control, pollination, and nutrient sharing.

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Plan Your Garden with Confidence

Get our free Garden Planner — organize your planting dates for Zone 4a, track your crops, and plan your garden season from seed to harvest.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals, University Cooperative Extension planting guides. Planting dates are estimates based on average frost dates — local conditions may vary. Last updated: April 2026.