When to Plant Shiso in USDA Zone 4a
Top priorities for Zone 4a gardeners in May
Your garden in Zone 4a is working on a schedule, even when you're not. Here's where you should be this May.
-
Sow shiso where they'll grow
Keep the top inch of soil moist until germination — a gentle morning watering for 5–7 days does the job.
June will be here before you know it — start on
- Transplants going out: shiso
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 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.
Shiso 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 Shiso planting schedule for that location.
Shiso Planting Calendar — Zone 4a
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 11 | Mar 11 – Mar 25 |
| Transplant Outdoors | May 27 | May 27 – Jun 10 |
| Direct Sow | May 13 | May 13 – Jun 3 |
| Harvest | July 22 | Jul 22 – Sep 16 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| 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 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.
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
145 days (Zone average)
Planting Specifications
| Planting Depth | 0.5 inches |
| Plant Spacing | 8 inches apart |
| Row Spacing | 12 inches between rows |
Succession Planting Shiso in Zone
Sow every 5.7 weeks for continuous harvest throughout the season.
Growing Tips for Shiso in Zone
Zone has a short growing season (~145 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
Start seeds indoors with reusable cell trays and humidity domes.
Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.
Keep your garden organized with durable, weather-resistant plant labels.
Related Plants
Shiso in Other Zones
Shiso by State
- Alabama
- Alaska
- Arizona
- Arkansas
- California
- Colorado
- Connecticut
- Delaware
- Florida
- Georgia
- Hawaii
- Idaho
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Maine
- Maryland
- Massachusetts
- Michigan
- Minnesota
- Mississippi
- Missouri
- Montana
- Nebraska
- Nevada
- New Hampshire
- New Jersey
- New Mexico
- New York
- North Carolina
- North Dakota
- Ohio
- Oklahoma
- Oregon
- Pennsylvania
- Rhode Island
- South Carolina
- South Dakota
- Tennessee
- Texas
- Utah
- Vermont
- Virginia
- Washington
- West Virginia
- Wisconsin
- Wyoming
Frequently Asked Questions
When should I plant Shiso in Zone 4a?
In Zone 4a, plan your Shiso planting around the average last frost date of May 6. Start seeds indoors around March 11. Direct sow outdoors around May 13. Transplant seedlings around May 27.
Can Shiso grow in Zone 4a?
Yes, Shiso can grow well in Zone 4a, hardy in USDA zones 3a through 11b. Zone 4a has a growing season of approximately 145 days, which is sufficient for Shiso (50-70 days to maturity).
When can I harvest Shiso in Zone 4a?
In Zone 4a, expect to harvest Shiso from July 22 – September 16. Shiso takes 50-70 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 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.