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When to Plant Komatsuna in USDA Zone 8b

Zone 8b Zone 8b April

This month in Zone 8b

April is a pivotal month for Zone 8b gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost March 16
Avg. first frost November 13
  1. Time to start komatsuna inside

    You're about 28 weeks out from your last frost — the perfect window to get these germinating indoors.

  2. Basket week: komatsuna

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

May prep starts now
  • First harvests: komatsuna
Want it on paper? Download your Zone 8b 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 8b, the average last spring frost is around February 25 and the first fall frost is around November 28, giving you a growing season of approximately 276 days.

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Zone 8b Year-round
276 days
Last Spring Frost February 25
276 growing days
First Fall Frost November 28

Komatsuna Planting Timeline — Zone 8b

Where Is USDA Zone 8b?

The map below highlights the states that contain Zone 8b. Click any state to see the Komatsuna planting schedule for that location.

Prints a clean, ink-friendly version without maps or navigation.

Komatsuna Planting Calendar — Zone 8b

Activity When Date Range
Start Indoors January 21 Jan 21 – Feb 4
Transplant Outdoors February 25 Feb 25 – Mar 11
Direct Sow February 11 Feb 11 – Mar 4
Harvest April 1 Apr 1 – May 6
Fall Sowing September 19 Sep 19 – Oct 3

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

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

Free Zone 8b Planting Calendar PDF

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

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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

276 days (Zone average)

Planting Specifications

Planting Depth0.5 inches
Plant Spacing6 inches apart
Row Spacing12 inches between rows

Succession Planting Komatsuna in Zone

9
successive plantings in Zone 's ~276-day season

Sow every 4 weeks for continuous harvest throughout the season.

Growing Tips for Komatsuna in Zone

Zone has a short growing season (~276 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

  • Strawberries
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Saving Komatsuna 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 Komatsuna in Zone 8b?

In Zone 8b, plan your Komatsuna planting around the average last frost date of February 25. Start seeds indoors around January 21. Direct sow outdoors around February 11. Transplant seedlings around February 25.

Can Komatsuna grow in Zone 8b?

Yes, Komatsuna can grow well in Zone 8b, hardy in USDA zones 2a through 11b. Zone 8b has a growing season of approximately 276 days, which is sufficient for Komatsuna (35-50 days to maturity).

When can I harvest Komatsuna in Zone 8b?

In Zone 8b, expect to harvest Komatsuna from April 1 – May 6. Komatsuna takes 35-50 days from planting to harvest.

What is the last frost date for Zone 8b?

The average last spring frost in Zone 8b is around February 25, and the first fall frost is around November 28. This gives a growing season of approximately 276 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.

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: April 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.