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When to Plant Shiso in USDA Zone 3a

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 3a, the average last spring frost is around May 15 and the first fall frost is around September 15, giving you a growing season of approximately 123 days.

Zone 3a Short season
123 days
Last Spring Frost May 15
123 growing days
First Fall Frost September 15

Shiso Planting Timeline — Zone 3a

Where Is USDA Zone 3a?

The map below highlights the states that contain Zone 3a. 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 3a

Activity When Date Range
Start Indoors March 20 Mar 20 – Apr 3
Transplant Outdoors June 5 Jun 5 – Jun 19
Direct Sow May 22 May 22 – Jun 12
Harvest July 31 Jul 31 – Sep 25

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

Month-by-Month Timeline

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

Free Zone 3a Planting Calendar PDF

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

-40°F to -35°F average annual minimum

Growing Season

123 days (Zone 3a average)

Planting Specifications

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

Succession Planting Shiso in Zone 3a

2
successive plantings in Zone 3a's ~123-day season

Sow every 5.7 weeks for continuous harvest throughout the season.

Growing Tips for Shiso in Zone 3a

Zone 3a has a short growing season (~123 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

Good Companions

Level Up Your Garden

Saving Shiso Seeds

Recommended for Your Garden

💡
LED Grow Lights $25-60

Full-spectrum LED lights for starting seeds indoors when daylight is limited.

🔥
Seedling Heat Mat $15-35

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

🪡
Floating Row Covers $12-30

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

Related Plants

Frequently Asked Questions

When should I plant Shiso in Zone 3a?

In Zone 3a, plan your Shiso planting around the average last frost date of May 15. Start seeds indoors around March 20. Direct sow outdoors around May 22. Transplant seedlings around June 5.

Can Shiso grow in Zone 3a?

Yes, Shiso can grow well in Zone 3a, hardy in USDA zones 3a through 11b. Zone 3a has a growing season of approximately 123 days, which is sufficient for Shiso (50-70 days to maturity).

When can I harvest Shiso in Zone 3a?

In Zone 3a, expect to harvest Shiso from July 31 – September 25. Shiso takes 50-70 days from planting to harvest.

What is the last frost date for Zone 3a?

The average last spring frost in Zone 3a is around May 15, and the first fall frost is around September 15. This gives a growing season of approximately 123 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.

🌱

Plan Your Garden with Confidence

Get our free Garden Planner — organize your planting dates for Zone 3a, 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.