Blog

When to Plant Shiso in USDA Zone 8a

Zone 8a Zone 8a May

May in the garden — Zone 8a

We've pulled the most time-sensitive tasks for Zone 8a this May and put them front and centre. Tackle them in order.

Avg. last frost March 28
Avg. first frost November 6
  1. Sow shiso in trays indoors

    You're about 26 weeks out from your last frost — the perfect window to get these germinating indoors.

A few tasks this May that'll pay off in June
  • First harvests: shiso
Download your personalised Zone 8a planting plan →

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 8a, the average last spring frost is around March 8 and the first fall frost is around November 18, giving you a growing season of approximately 255 days.

Share this guide:
Zone 8a Long season
255 days
Last Spring Frost March 8
255 growing days
First Fall Frost November 18

Shiso Planting Timeline — Zone 8a

Where Is USDA Zone 8a?

The map below highlights the states that contain Zone 8a. 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 8a

Activity When Date Range
Start Indoors January 18 Jan 18 – Feb 1
Transplant Outdoors March 22 Mar 22 – Apr 5
Direct Sow March 15 Mar 15 – Apr 5
Harvest May 17 May 17 – Jul 12

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

Month-by-Month Timeline

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

Free Zone 8a Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 8a with start dates, transplant windows, and harvest times.

Instant PDF download. No spam, unsubscribe any time.

Share this guide:

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

255 days (Zone average)

Planting Specifications

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

Succession Planting Shiso in Zone

6
successive plantings in Zone 's ~255-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 (~255 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

Best Seller
The Gardener's Encyclopedia to Companion Planting

The Gardener's Encyclopedia to Companion Planting

$27 $293 value

The pairings that make vegetables, herbs, and flowers grow better — and the ones that quietly wreck a bed.

  • Proven pairings for 200+ vegetables, herbs, flowers, and fruits
  • Full seed-starting + planting schedule with timing and spacing
  • Bonus: square-foot gardening guide + printable seasonal planners
See what's inside →

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 8a?

In Zone 8a, plan your Shiso planting around the average last frost date of March 8. Start seeds indoors around January 18. Direct sow outdoors around March 15. Transplant seedlings around March 22.

Can Shiso grow in Zone 8a?

Yes, Shiso can grow well in Zone 8a, hardy in USDA zones 3a through 11b. Zone 8a has a growing season of approximately 255 days, which is sufficient for Shiso (50-70 days to maturity).

When can I harvest Shiso in Zone 8a?

In Zone 8a, expect to harvest Shiso from May 17 – July 12. Shiso takes 50-70 days from planting to harvest.

What is the last frost date for Zone 8a?

The average last spring frost in Zone 8a is around March 8, and the first fall frost is around November 18. This gives a growing season of approximately 255 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.

Instant PDF download. No spam, unsubscribe any time.

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.