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When to Plant Mustard Greens in USDA Zone 4b

Zone 4b Zone 4b May

What to do in May

Your garden in Zone 4b is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost May 11
Avg. first frost October 2
  1. Get mustard greens in the ground

    Frost risk is low now in Zone 4b. If you've been covering beds overnight, you can stop.

  2. Plant mustard greens from seed, right in the garden

    Thin ruthlessly once seedlings are up. Crowded roots mean smaller crops from every plant.

June prep starts now
  • Starting indoors: mustard greens
  • First harvests: mustard greens
Send me my free Zone 4b 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 4b, the average last spring frost is around May 1 and the first fall frost is around October 3, giving you a growing season of approximately 155 days.

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Zone 4b Moderate season
155 days
Last Spring Frost May 1
155 growing days
First Fall Frost October 3

Mustard Greens Planting Timeline — Zone 4b

Where Is USDA Zone 4b?

The map below highlights the states that contain Zone 4b. 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 4b

Activity When Date Range
Start Indoors March 20 Mar 20 – Apr 3
Transplant Outdoors May 1 May 1 – May 15
Direct Sow April 24 Apr 24 – May 15
Harvest June 5 Jun 5 – Aug 7
Fall Sowing July 11 Jul 11 – Jul 25

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

Month-by-Month Timeline

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

Free Zone 4b Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 4b 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

155 days (Zone average)

Planting Specifications

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

Succession Planting Mustard Greens in Zone

6
successive plantings in Zone 's ~155-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 (~155 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 4b?

In Zone 4b, plan your Mustard Greens planting around the average last frost date of May 1. Start seeds indoors around March 20. Direct sow outdoors around April 24. Transplant seedlings around May 1.

Can Mustard Greens grow in Zone 4b?

Yes, Mustard Greens can grow well in Zone 4b, hardy in USDA zones 2a through 11b. Zone 4b has a growing season of approximately 155 days, which is sufficient for Mustard Greens (30-50 days to maturity).

When can I harvest Mustard Greens in Zone 4b?

In Zone 4b, expect to harvest Mustard Greens from June 5 – August 7. Mustard Greens takes 30-50 days from planting to harvest.

What is the last frost date for Zone 4b?

The average last spring frost in Zone 4b is around May 1, and the first fall frost is around October 3. This gives a growing season of approximately 155 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.

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: May 2026.

Sources & credits

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