When to Plant Komatsuna in USDA Zone 6b
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 6b, the average last spring frost is around April 3 and the first fall frost is around October 25, giving you a growing season of approximately 205 days.
Komatsuna Planting Timeline — Zone 6b
Where Is USDA Zone 6b?
The map below highlights the states that contain Zone 6b. Click any state to see the Komatsuna planting schedule for that location.
Komatsuna Planting Calendar — Zone 6b
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 27 | Feb 27 – Mar 13 |
| Transplant Outdoors | April 3 | Apr 3 – Apr 17 |
| Direct Sow | March 20 | Mar 20 – Apr 10 |
| Fall Sowing | August 16 | Aug 16 – Aug 30 |
| Harvest | May 8 | May 8 – Jun 12 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | Harvest |
| June | Harvest |
| July | — |
| August | Fall Sowing |
| September | — |
| October | — |
| November | — |
| December | — |
Free Zone 6b Planting Calendar PDF
Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 6b 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
-5°F to 0°F average annual minimum
Growing Season
205 days (Zone 6b average)
Planting Specifications
| Planting Depth | 0.5 inches |
| Plant Spacing | 6 inches apart |
| Row Spacing | 12 inches between rows |
Growing Tips for Zone 6b
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 6b?
In Zone 6b, plan your Komatsuna planting around the average last frost date of April 3. Start seeds indoors around February 27. Direct sow outdoors around March 20. Transplant seedlings around April 3.
Can Komatsuna grow in Zone 6b?
Yes, Komatsuna can grow well in Zone 6b, hardy in USDA zones 2a through 11b. Zone 6b has a growing season of approximately 205 days, which is sufficient for Komatsuna (35-50 days to maturity).
When can I harvest Komatsuna in Zone 6b?
In Zone 6b, expect to harvest Komatsuna from May 8 – June 12. Komatsuna takes 35-50 days from planting to harvest.
What is the last frost date for Zone 6b?
The average last spring frost in Zone 6b is around April 3, and the first fall frost is around October 25. This gives a growing season of approximately 205 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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