How to Plant, Grow, and Care for Mustard Greens

Mustard is an excellent cool-season crop with interesting leaves ranging from purple to bright green. Mustard can taste mild, or it can be spicy and peppery. It is a favorite in southern gardens. Growing mustard greens is simple, and they are high in antioxidants, a good source of fiber, and high in vitamins A and C. 

Mustard greens are popular in a variety of dishes, from microgreens to curries and stir-fries. They have been consumed for more than 5,000 years. They were originally grown in Asia and the Mediterranean, and today, countries like India, Nepal, China, and Japan are the leading growers of this delicious green. In addition to being prized for its leaves, mustard can be grown for its seeds, which are used to make the condiment mustard. 

Mustard greens include a variety of species such as black mustard, white mustard, brown mustard, and more! Other members of the mustard family include tatsoi, mizuna, and bok choy. Mustards are also related to other Brassicas such as broccoli, kale, cabbage, and cauliflower. Growing mustard is easy and can provide nutritious leafy greens and seeds. Let’s talk more about it. 

What are Mustard Greens?

Mustard is an easy to grow annual cool weather leafy green that is grown for its spicy leaves, seeds, and edible tuber root. There are several common varieties of mustard, including black mustard (Brassica nigra), white mustard (Sinapis alba), and brown mustard (Brassica juncea). 

Brassica nigra, or black mustard, is considered invasive in some places. It produces allopathic chemicals that prevent other plants from growing where it is growing. Garlic mustard, or Alliaria petiolata, and brown mustard, Brassica juncea, are also considered invasive in some locations. The best way to stop their spread is to cut off any flowers that form to prevent them from going to seed. You can also cut it down at soil level and remove all organic matter. 

Native Area

Mustard primarily originates from regions around the Mediterranean and in Southern Asia. It is now grown in most parts of the world, with China, India, and Japan as the leaders in growing mustard for greens and for seed.

Mustard can play a part in increasing forest fires because it establishes itself in large patches. These patches can then become fodder for wildfires in habitats that do not normally experience fires. In California, gardeners have been encouraged to cook and eat wild mustard or otherwise use it for medicinal and edible purposes as part of a strategy to control the invasive wild mustard population.

Characteristics

Mustard greens grow in a rosette of upright leaves, often several inches tall. A few of the spicier-tasting varieties have a frizzy shape. A bigger mustard leaf can be used in stir-fries, while a smaller mustard leaf is better for eating raw. Mustard greens are also a popular microgreen. They have a bulbous white taproot that is similar to other root vegetables. The roots are edible and have a strong taste.  

As a cool-season crop, mustard tends to bolt when the weather gets warmer in spring. After the plant produces tiny yellow umbel-shaped flowers, small seed pods will form and turn brown. Mustard greens that are allowed to naturally flower through a slower life cycle rather than bolting will produce better seeds for culinary use.

Varieties

There are many mustard varieties that are prized for their color, spicy or mild taste, or resistance to bolting. ‘Crimson Red’ is a variety with deep burgundy leaves and a medium spicy taste. ‘Red Giant’ is another red variety that is extremely fast-growing and productive. ‘Golden Frills’ has a frilly green leaf, is slow to bolt, and has a very spicy taste. ‘Southern Giant’ is a large plant that is also slow to bolt, and ‘Florida Broadleaf’ features large, green leaves with a mild taste. Plant mustard greens like ‘Bekana’ for a mild taste similar to lettuce with mild frost tolerance. 

Planting

Mustard greens grow well in cool weather, which means you can grow mustard greens in both spring and fall. Plant mustard greens in spring as early as four to six weeks before your last frost date. You can sow seeds in the garden for several weeks in spring before the weather gets too hot. You can also sow seeds in late summer up until the last frost. 

Mustard greens must be sown in rich soil amended with organic matter for nutrition and good drainage. You can grow mustard in containers or raised garden beds. If planting in-ground, be sure to confirm that the variety of mustard greens you are planting is not invasive in your area. 

You can sow mustard by sprinkling seeds on the soil surface and covering them lightly with additional soil, or they can be planted in holes that are a quarter-inch deep. You can also start seeds indoors and transplant them outdoors. They will perform well in containers, raised beds, or even in amended soil in the ground. Set seedlings about six to eight inches apart. 

How to Grow

Now that you have your mustard greens started, let’s talk about how to get your mustard greens growing for an epic harvest. 

Light

Grow mustard in full sun to part shade. It can grow in as little as four to six hours of direct sunlight per day, and you can grow mustard greens in your garden anywhere from zones 2 through 11. They will grow best in six to eight hours of sunlight. 

Water and Humidity

Water your mustard greens in the early morning. You should provide two inches per week, making sure the soil does not dry out. The ideal way to water is at the base of the plant, taking care to keep the mustard green plant dry, which can cause diseases. Soaker hoses or other methods of drip irrigation work extremely well.

Grow mustard greens in moist soil. If you want a spicier taste, water your mustard less. This will cause the plant to secrete oils and develop a stronger, spicier flavor. Be careful to not completely dry it out, or else it will go to seed. 

Soil

Mustard greens prefer a light and fluffy mix of loamy soil that is rich in organic matter. They can be grown in poorer soil but will need to be watered and fertilized more often. Mustard does well in soils with a pH ranging from 5.5 to 7.0.

Temperature

Grow mustard greens in temperatures between 50-75°F (10-24°C). Temperature fluctuations can stress it and cause it to bolt, flowering and setting seed. In weather hotter than 85°F (29°C), the leaves will develop a spicy and strong flavor. If planting in the fall in a hot climate, you can protect your mustard greens with a shade cloth until temperatures are consistently cooler.

Mustard greens have good cold-weather tolerance. The curly-leaved varieties can handle frost better than other types of straight-leaved mustard greens, and mild frost will actually make it taste sweeter. However, a true freeze in the garden will kill it. 

Fertilizing

If the soil in your vegetable garden is already rich, you may not need to add fertilize. If you are planting in poorer quality soil, such as sandy soil, apply a balanced fertilizer when they are a few inches tall, and then again at the midway point of your growing season. Slow-release will ensure the fast-growing mustards have access to a steady supply of nutrients. If the leave are yellow or show signs of deficiencies, opt for a liquid fertilizer to feed them faster. Mustard greens require a high amount of nitrogen and moderate phosphorus and potassium. 

Maintenance

Mustards are an annual that will not require pruning. If you are growing for mustard seeds, do not cut the top off or deadhead it, as this will stop it from developing flowers and seeds. 

Harvesting

Now let’s talk more about harvesting and storing your mustard greens. 

You can harvest mustard greens after about 40 days, or six weeks. This may vary slightly based on the variety, but for a sweeter taste, harvest when it is young and tender. If you prefer a spicier, more peppery taste, allow the mustard to grow to full maturity. 

When harvesting mustard greens, you can cut the outer leaves to harvest them, which will allow the inner leaves to continue growing. You can also cut the entire vegetable off at soil level to harvest it, and it will eventually regrow small leaves if you leave the roots intact, although this new growth tends to be smaller and bitter. If you are harvesting during the heat of the day, you can put freshly cut greens into ice water to keep them green and prevent them from wilting. 

Storage

Store fresh greens in the refrigerator in cold water to maintain perky leaves. You can also store the greens in a bag with a wet paper towel for moisture. Mustard greens can last about one week in the refrigerator.

If you need to save them for a longer period of time, try blanching them by quickly boiling and then plunging them into an ice bath before freezing. This will preserve most of the taste and nutrients for later. You can also dice the leaves and dry them in the dehydrator to create a nutrient-packed powder. 

Additionally, mustard can be grown for its seeds. Once you harvest the seeds, you will need to separate the seeds from the chaff, or dried parts. Take the seeds in a bowl in front of a fan and slowly pour them into another container. The dried material should blow away, and the seeds should fall directly into your container. You may need to repeat this process several times to remove all stems and leaves material. Finally, when your seeds have been separated, store them in a dry, air-tight container, or grind them up to create a mustard powder. 

Common Problems

Now let’s talk about some issues you might encounter while growing mustard greens. 

Growing Problems

If you have poor soil, your mustard greens may be nutrient deficient. If you notice yellowing leaves, you may need more nitrogen. Try using a liquid kelp meal or liquid fish fertilizer diluted in water to give them a nitrogen boost. You can also add compost or well-aged manure to improve the organic matter in the soil over time. 

Mustard grows best in well-drained soil. Plant your mustard greens in containers that have holes in the bottom so excess water can drain off. Be sure to keep your mustards watered consistently so that the leaves can grow and develop properly. 

Keep the area where you are growing your mustard greens weed-free so that the small seedlings have room to sprout and are not out-competed by weeds. If you planted seeds by sprinkling them onto the soil surface, you will also need to thin out seedlings, so that some can grow larger. Otherwise, all of your seedlings will compete for space and nutrients, and you will have a smaller harvest. 

Pests

Aphids will enjoy eating the leaves. You can spray them off with a hose, or use neem oil to get rid of them. Cabbage worms may attack those in the cabbage family if they are planted too closely together, so be sure to keep mustard properly spaced and check regularly for any caterpillars. You can handpick them or use a Bt spray. 

Another pest, flea beetles, will chew holes in large leaves like the ‘Florida Broadleaf’. They can be prevented by using a floating row cover over your seedlings. You may also need to rotate crops and grow another vegetable family for a few seasons to get rid of flea beetles. 

Whiteflies can also be an issue, but can easily be killed by spraying with insecticidal soap.

Diseases

White spot, which is caused by Cercosporella brassicae, causes grey or brown spots and can be transferred between wild mustard and mustard growing in the garden. Peronospora parasitica, which causes downy mildew, creates white splotches on the vegetable.

Sooty mildew and most diseases that affect mustard greens can be controlled by good care. You should grow seedlings in a fresh sterile potting mix every time, and water at the soil level. Never water leafy greens from overhead if possible because this can encourage disease. There are many organic products on the market for handling these diseases.

Severely diseased mustards beyond the point of treatment should be removed from the garden immediately and disposed of. You should not compost them, as the disease may survive and infect other vegetables. 

Finally, you should grow members of the cabbage family apart from each other so one pest cannot destroy your entire crop at once, and you should practice good crop rotation so pests do not build up in your garden.

Frequently Asked Questions