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When to Plant Shiso in USDA Zone 3b

Zone 3b Zone 3b May

Your May gardening checklist

Each item below is timed to Zone 3b's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 16
Avg. first frost September 22
  1. Scatter shiso into prepared beds

    Succession planting is the secret here. Put in a row now, another in 2 weeks, a third in 4.

June will be here before you know it — start on
  • Transplants going out: shiso
Want it on paper? Download your Zone 3b planting guide →

Shiso (perilla) is a fragrant Japanese herb with large, ruffled leaves in green or purple varieties. It has a unique flavor combining mint, basil, and anise.

In Zone 3b, the average last spring frost is around May 10 and the first fall frost is around September 22, giving you a growing season of approximately 135 days.

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Zone 3b Short season
135 days
Last Spring Frost May 10
135 growing days
First Fall Frost September 22

Shiso Planting Timeline — Zone 3b

Where Is USDA Zone 3b?

The map below highlights the states that contain Zone 3b. Click any state to see the Shiso planting schedule for that location.

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

Shiso Planting Calendar — Zone 3b

Activity When Date Range
Start Indoors March 15 Mar 15 – Mar 29
Transplant Outdoors May 31 May 31 – Jun 14
Direct Sow May 17 May 17 – Jun 7
Harvest July 26 Jul 26 – Sep 20

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

Month-by-Month Timeline

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

Free Zone 3b Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 3b 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

50–70 days

Soil pH

5.5 – 7

Zone Temperature Range

°F to °F average annual minimum

Growing Season

135 days (Zone average)

Planting Specifications

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

Succession Planting Shiso in Zone

3
successive plantings in Zone 's ~135-day season

Sow every 5.7 weeks for continuous harvest throughout the season.

Growing Tips for Shiso in Zone

Zone has a short growing season (~135 days). Start Shiso indoors early and use season-extension techniques like row covers and cold frames.

Direct sow after last frost or start indoors. Both green and red varieties are available. Pinch tips to encourage bushiness. Self-sows prolifically; deadhead to control.

Companion Planting

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Saving Shiso Seeds

Recommended for Your Garden

🌱
Seed Starting Trays $8-20

Start seeds indoors with reusable cell trays and humidity domes.

🧪
Soil Test Kit $12-25

Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.

🏷️
Garden Plant Markers $6-12

Keep your garden organized with durable, weather-resistant plant labels.

Related Plants

Frequently Asked Questions

When should I plant Shiso in Zone 3b?

In Zone 3b, plan your Shiso planting around the average last frost date of May 10. Start seeds indoors around March 15. Direct sow outdoors around May 17. Transplant seedlings around May 31.

Can Shiso grow in Zone 3b?

Yes, Shiso can grow well in Zone 3b, hardy in USDA zones 3a through 11b. Zone 3b has a growing season of approximately 135 days, which is sufficient for Shiso (50-70 days to maturity).

When can I harvest Shiso in Zone 3b?

In Zone 3b, expect to harvest Shiso from July 26 – September 20. Shiso takes 50-70 days from planting to harvest.

What is the last frost date for Zone 3b?

The average last spring frost in Zone 3b is around May 10, and the first fall frost is around September 22. This gives a growing season of approximately 135 days. These are 50% probability dates — actual frost dates vary year to year.

What should I plant next to Shiso?

Good companion plants for Shiso include Tomatoes, Peppers. 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: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.