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When to Plant Yarrow in USDA Zone 4a

Zone 4a Zone 4a April

What to do in April

April is a pivotal month for Zone 4a gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 13
Avg. first frost September 29
May will be here before you know it — start on
  • Transplants going out: yarrow
Want it on paper? Download your Zone 4a planting guide →

Yarrow is a drought-tolerant perennial herb with feathery foliage and flat-topped flower clusters in white, yellow, pink, or red. It attracts beneficial insects and is used in herbal medicine.

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.

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

Yarrow 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 Yarrow planting schedule for that location.

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

Yarrow Planting Calendar — Zone 4a

Activity When Date Range
Transplant Outdoors May 13 May 13 – May 27
Harvest August 12 Aug 12 – 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 Harvest
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

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

Days to Maturity

90–120 days

Soil pH

5.5 – 7

Zone Temperature Range

°F to °F average annual minimum

Growing Season

145 days (Zone average)

Planting Specifications

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

Growing Tips for Yarrow in Zone

Zone has a short growing season (~145 days). Start Yarrow indoors early and use season-extension techniques like row covers and cold frames.

Direct sow or start from divisions. Yarrow thrives in poor soil and is very drought-tolerant. Deadhead to encourage reblooming. Divide clumps every 3 years.

Companion Planting

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Saving Yarrow Seeds

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Frequently Asked Questions

When should I plant Yarrow in Zone 4a?

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

Can Yarrow grow in Zone 4a?

Yes, Yarrow 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 Yarrow (90-120 days to maturity).

When can I harvest Yarrow in Zone 4a?

In Zone 4a, expect to harvest Yarrow from August 12 – October 7. Yarrow takes 90-120 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 Yarrow?

Good companion plants for Yarrow include Lavender, Rosemary, Thyme. These companions can help with pest control, pollination, and nutrient sharing.

🌱

Your Free Printable Garden Planner

A 24-page printable planner tailored to your zone. Planting dates, monthly task lists, harvest log, seed inventory, and succession charts — everything you need to plan a full season.

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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.

Sources & credits

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