How to Grow Mustard Greens: The Complete Guide

Growing Mustard Greens
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saypinarcs
Botanical Name
Brassica juncea
Plant Type
Sun Exposure
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Hardiness Zone
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Planting, Growing, and Harvesting Mustard Greens

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Need a little lift in your life? Need some sass in your salad? Discover mustard greens! To the uninitiated, we’ll explain what nutritious, spicy mustard greens are—and how to grow these annual vegetables in garden beds or containers.

About Mustard Greens

While many people lump them in as “greens,” mustard greens are quite different from collards or kale. Mustard greens are known botanically as Brassica juncea. An annual, they grow, flower, seed, and die all in one year. They are hardy annuals, meaning they can take some cold temperatures, and their flavor is best if grown as a spring or fall crop. 

Mustard greens have thinner, more tender leaves than collards or kale. Their foliage can be many shades of light to deep green and purple. Leaf edges may be smooth, frilly, or lacey; some can grow large. Known for their spicy flavor, mustard greens are excellent additions to salads, sandwiches, smoothies, and juices. They are often cooked down and added to dishes to bring a shot of flavor and a bit of heat. 

Mustard greens bloom with dozens of small yellow flowers. It has been listed as an invasive species in New Hampshire and Michigan.  Many websites will list “mustard” as invasive, so search for the plant with the botanical name instead. While several plants with mustard in their common name are invasive, such as garlic mustard (Alliaria petiolata) and wild mustard (Brassica arvensis), most states do not list B. juncea as an invasive. If you are concerned, remember to remove the flowers, and it won’t make seed and spread. After all, we want the tasty foliage!

Planting

Mustard greens like neutral soil, with a pH of 6.5-7.5, but they will grow in less than ideal conditions. The fastest growth is in full sun, but a partial sun location will work. They like evenly moist soil rich in organic matter; adequate drainage is still required–don’t plant them on a wet site. 

Mustard greens can also be grown in containers! Choose a pot that is at least 3 gallons for full-size plants. Baby mustard can be grown in smaller containers.

When to Plant Mustard greens

Mustard greens are typically planted in early spring and late summer for a fall crop. However, depending on your climate, you may be able to plant mustard greens throughout the entire season. The seeds will germinate in the soil as cool as 40 degrees. 

Generally, sowing seeds 3 to 4 weeks before your last frost is a good starting point. Succession plant every 2 to 3 weeks for a continuous supply of tender leaves. 

How to Plant Mustard Greens

  • Work in compost or aged manure and mulch around plants after they emerge. 
     
  • Directly sow seeds in the prepared ground, about ¼ inch deep, and cover lightly. 
     
  • Baby mustard greens can be planted close together, about two seeds per inch, with rows 4-6 inches apart. 
     
  • If you plan to allow your mustard greens to grow larger, leave 12 to 18 inches between rows and 6 to 12 inches between plants, depending on the variety. 

Growing

Mustard greens can be lush and reach an impressive size. Like other greens, they not only taste good but are great at making your garden look inviting, and you like you’ve got a green thumb.

  • Mustard greens like fertile soil rich in organic matter. This is the spot to use a little extra compost or aged manure. All that nitrogen as the organic material breaks down is just what those greens like. 
     
  • Keep soil moisture levels even by mulching. Check the soil moisture by working your finger down 2-3 inches. The soil should be cool and a little damp. If it is hot and dusty, you’ll need to water.
     
  • Check your rain gauge and provide extra water if necessary. Mustard greens like about an inch of water per week, more in hot or dry weather. Two deep waterings are better than daily shallow irrigation.
     
  • Water in the morning to reduce issues with fungal diseases. Leaves will dry faster in the heat of the day, minimizing how long they are damp and supportive of spores. 

Harvesting

Mustard greens can be harvested as baby greens about 3-4 weeks after sowing or allowed to get larger. Of course, if you seed them closely and then eat the ones that need thinning, that provides both sizes. 

Greens harvested before hot weather will be more mild and tender. For mature plants, grab the base of the leaf and twist it off. Mustard greens are cut and come again, meaning they will continue to send new leaves and provide a long harvest season. Baby mustard greens can be snipped off with scissors.

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Wit and Wisdom

  • Many gardeners find curly-leaved varieties tolerate frosts better than straight-leaved plants.
     
  • Mustard greens contain more Vitamin A than spinach and more Vitamin C than oranges.
     
  • These spicy greens are loaded with antioxidants called phytonutrients. 

Pests/Diseases

  • Flea beetles (use row covers)
     
  • Slugs
     
  • Aphids
     
About The Author

Andy Wilcox

Andy Wilcox is a flower farmer and master gardener with a passion for soil health, small producers, forestry, and horticulture. Read More from Andy Wilcox