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When to Plant Shiso in USDA Zone 9b

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 9b, the average last spring frost is around January 25 and the first fall frost is around December 20, giving you a growing season of approximately 329 days.

Zone 9b Year-round
329 days
Last Spring Frost January 25
329 growing days
First Fall Frost December 20

Shiso Planting Timeline — Zone 9b

Where Is USDA Zone 9b?

The map below highlights the states that contain Zone 9b. 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 9b

Activity When Date Range
Start Indoors December 14 Dec 14 – Dec 28
Transplant Outdoors February 1 Feb 1 – Feb 15
Direct Sow February 1 Feb 1 – Feb 22
Harvest March 29 Mar 29 – May 24

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

Month-by-Month Timeline

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

Free Zone 9b Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 9b 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

25°F to 30°F average annual minimum

Growing Season

329 days (Zone 9b average)

Planting Specifications

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

Succession Planting Shiso in Zone 9b

7
successive plantings in Zone 9b's ~329-day season

Sow every 5.7 weeks for continuous harvest throughout the season.

Growing Tips for Shiso in Zone 9b

Zone 9b offers a long growing season (~329 days). You can plant Shiso earlier and may get multiple harvests.

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

☀️
Garden Shade Cloth $15-35

Reduce heat stress and sun scorch in hot climates with UV-stabilized shade cloth.

🌱
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.

Related Plants

Frequently Asked Questions

When should I plant Shiso in Zone 9b?

In Zone 9b, plan your Shiso planting around the average last frost date of January 25. Start seeds indoors around December 14. Direct sow outdoors around February 1. Transplant seedlings around February 1.

Can Shiso grow in Zone 9b?

Yes, Shiso can grow well in Zone 9b, hardy in USDA zones 3a through 11b. Zone 9b has a growing season of approximately 329 days, which is sufficient for Shiso (50-70 days to maturity).

When can I harvest Shiso in Zone 9b?

In Zone 9b, expect to harvest Shiso from March 29 – May 24. Shiso takes 50-70 days from planting to harvest.

What is the last frost date for Zone 9b?

The average last spring frost in Zone 9b is around January 25, and the first fall frost is around December 20. This gives a growing season of approximately 329 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 9b, track your crops, and plan your garden season from seed to harvest.

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Free download. Plan your entire garden season in minutes.

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.