When to Plant Komatsuna in USDA Zone 6a
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 6a, the average last spring frost is around April 10 and the first fall frost is around October 20, giving you a growing season of approximately 193 days.
Komatsuna Planting Timeline — Zone 6a
Where Is USDA Zone 6a?
The map below highlights the states that contain Zone 6a. Click any state to see the Komatsuna planting schedule for that location.
Komatsuna Planting Calendar — Zone 6a
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 6 | Mar 6 – Mar 20 |
| Transplant Outdoors | April 10 | Apr 10 – Apr 24 |
| Direct Sow | March 27 | Mar 27 – Apr 17 |
| Fall Sowing | August 11 | Aug 11 – Aug 25 |
| Harvest | May 15 | May 15 – Jun 19 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | Harvest |
| June | Harvest |
| July | — |
| August | Fall Sowing |
| September | — |
| October | — |
| November | — |
| December | — |
Free Zone 6a Planting Calendar PDF
Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 6a 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
-10°F to -5°F average annual minimum
Growing Season
193 days (Zone 6a average)
Planting Specifications
| Planting Depth | 0.5 inches |
| Plant Spacing | 6 inches apart |
| Row Spacing | 12 inches between rows |
Growing Tips for Zone 6a
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
Level Up Your Garden
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
- Alberta
- Arizona
- Arkansas
- British Columbia
- California
- Colorado
- Connecticut
- Delaware
- Florida
- Georgia
- Hawaii
- Idaho
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Maine
- Manitoba
- Maryland
- Massachusetts
- Michigan
- Minnesota
- Mississippi
- Missouri
- Montana
- Nebraska
- Nevada
- New Brunswick
- New Hampshire
- New Jersey
- New Mexico
- New York
- Newfoundland and Labrador
- North Carolina
- North Dakota
- Northwest Territories
- Nova Scotia
- Nunavut
- Ohio
- Oklahoma
- Ontario
- Oregon
- Pennsylvania
- Prince Edward Island
- Quebec
- Rhode Island
- Saskatchewan
- South Carolina
- South Dakota
- Tennessee
- Texas
- Utah
- Vermont
- Virginia
- Washington
- West Virginia
- Wisconsin
- Wyoming
- Yukon
Frequently Asked Questions
When should I plant Komatsuna in Zone 6a?
In Zone 6a, plan your Komatsuna planting around the average last frost date of April 10. Start seeds indoors around March 6. Direct sow outdoors around March 27. Transplant seedlings around April 10.
Can Komatsuna grow in Zone 6a?
Yes, Komatsuna can grow well in Zone 6a, hardy in USDA zones 2a through 11b. Zone 6a has a growing season of approximately 193 days, which is sufficient for Komatsuna (35-50 days to maturity).
When can I harvest Komatsuna in Zone 6a?
In Zone 6a, expect to harvest Komatsuna from May 15 – June 19. Komatsuna takes 35-50 days from planting to harvest.
What is the last frost date for Zone 6a?
The average last spring frost in Zone 6a is around April 10, and the first fall frost is around October 20. This gives a growing season of approximately 193 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.
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