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When to Plant Mustard Greens in USDA Zone 9b

Zone 9b Zone 9b May

What to do in May

Here's what deserves your attention in Zone 9b this month. Everything below is tailored to Zone 9b and timed around your local frost dates.

Avg. last frost February 14
Avg. first frost December 4
  1. Bring in the mustard greens

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

Get your free Zone 9b 2026 Planting Guide →

Mustard greens are fast-growing brassicas with a spicy, peppery kick. They come in green, red, and purple varieties and are excellent cooked or in salads.

In Zone 9b, the average last spring frost is around January 25 and the first fall frost is around December 20, giving you a growing season of approximately 329 days.

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Zone 9b Year-round
329 days
Last Spring Frost January 25
329 growing days
First Fall Frost December 20

Mustard Greens Planting Timeline — Zone 9b

Where Is USDA Zone 9b?

The map below highlights the states that contain Zone 9b. Click any state to see the Mustard Greens planting schedule for that location.

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

Mustard Greens Planting Calendar — Zone 9b

Activity When Date Range
Start Indoors December 28 Dec 28 – Jan 11
Transplant Outdoors January 25 Jan 25 – Feb 8
Direct Sow January 4 Jan 4 – Jan 25
Harvest March 1 Mar 1 – May 3
Fall Sowing October 25 Oct 25 – Nov 8

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

Month-by-Month Timeline

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

Free Zone 9b Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 9b 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

30–50 days

Soil pH

6 – 7

Zone Temperature Range

°F to °F average annual minimum

Growing Season

329 days (Zone average)

Planting Specifications

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

Succession Planting Mustard Greens in Zone

13
successive plantings in Zone 's ~329-day season

Sow every 3.4 weeks for continuous harvest throughout the season.

Growing Tips for Mustard Greens in Zone

Zone has a short growing season (~329 days). Start Mustard Greens indoors early and use season-extension techniques like row covers and cold frames.

Direct sow in early spring or fall. Harvest young leaves for milder flavor. Plants bolt quickly in heat so grow as a cool-season crop or provide shade.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries
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Saving Mustard Greens 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 Mustard Greens in Zone 9b?

In Zone 9b, plan your Mustard Greens planting around the average last frost date of January 25. Start seeds indoors around December 28. Direct sow outdoors around January 4. Transplant seedlings around January 25.

Can Mustard Greens grow in Zone 9b?

Yes, Mustard Greens can grow well in Zone 9b, hardy in USDA zones 2a through 11b. Zone 9b has a growing season of approximately 329 days, which is sufficient for Mustard Greens (30-50 days to maturity).

When can I harvest Mustard Greens in Zone 9b?

In Zone 9b, expect to harvest Mustard Greens from March 1 – May 3. Mustard Greens takes 30-50 days from planting to harvest.

What is the last frost date for Zone 9b?

The average last spring frost in Zone 9b is around January 25, and the first fall frost is around December 20. This gives a growing season of approximately 329 days. These are 50% probability dates — actual frost dates vary year to year.

What should I plant next to Mustard Greens?

Good companion plants for Mustard Greens include Celery, Lettuce, Onion. 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.

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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: May 2026.

Sources & credits

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