When to Plant Komatsuna in USDA Zone 3a
What to do in May
We've pulled the most time-sensitive tasks for Zone 3a this May and put them front and centre. Tackle them in order.
Send me my free Zone 3a Planting Guide →Komatsuna (Japanese mustard spinach) is a versatile Asian green with glossy, dark leaves and a mild, sweet flavor. It is extremely cold-hardy and heat-tolerant.
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.
Komatsuna 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 Komatsuna planting schedule for that location.
Komatsuna Planting Calendar — Zone 3a
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 3 | Apr 3 – Apr 17 |
| Transplant Outdoors | May 15 | May 15 – May 29 |
| Direct Sow | May 8 | May 8 – May 29 |
| Harvest | June 19 | Jun 19 – Jul 24 |
| Fall Sowing | June 23 | Jun 23 – Jul 7 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Fall Sowing Harvest |
| July | Fall Sowing Harvest |
| August | — |
| September | — |
| 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.
Growing Conditions
Sun
Partial Shade (3-6 hours)
💧 Water
Moderate — regular watering
Days to Maturity
35–50 days
Soil pH
6 – 7.5
Zone Temperature Range
°F to °F average annual minimum
Growing Season
123 days (Zone average)
Planting Specifications
| Planting Depth | 0.5 inches |
| Plant Spacing | 6 inches apart |
| Row Spacing | 12 inches between rows |
Succession Planting Komatsuna in Zone
Sow every 4 weeks for continuous harvest throughout the season.
Growing Tips for Komatsuna in Zone
Zone has a short growing season (~123 days). Start Komatsuna indoors early and use season-extension techniques like row covers and cold frames.
Direct sow in spring or fall. One of the most forgiving Asian greens for all seasons. Harvest outer leaves or cut whole plants. Excellent for stir-fries, soups, or salads.
Companion Planting
Good Companions
Avoid Planting Near
The Gardener's Encyclopedia to Companion Planting
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Saving Komatsuna 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
Komatsuna in Other Zones
Komatsuna 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 Komatsuna in Zone 3a?
In Zone 3a, plan your Komatsuna planting around the average last frost date of May 15. Start seeds indoors around April 3. Direct sow outdoors around May 8. Transplant seedlings around May 15.
Can Komatsuna grow in Zone 3a?
Yes, Komatsuna can grow well in Zone 3a, hardy in USDA zones 2a through 11b. Zone 3a has a growing season of approximately 123 days, which is sufficient for Komatsuna (35-50 days to maturity).
When can I harvest Komatsuna in Zone 3a?
In Zone 3a, expect to harvest Komatsuna from June 19 – July 24. Komatsuna takes 35-50 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 Komatsuna?
Good companion plants for Komatsuna include Lettuce, Spinach, Radish. 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.