Are Mustards Annual or Perennial? (Mustard Plants Explained)

mustard plant

When you hear the word “mustard,” you probably don’t think of the color green. Most people are familiar with the yellow condiment that has made mustard famous, but the mustard sauce isn’t the only delicious product of the mustard plant. Enter the mustard green.

Mustard greens are a leafy, deliciously nutritious alternative to the run-of-the-mill lettuce and cabbage in your garden. From salads to sandwiches, mustard greens provide a tangy, crunchy change of pace in your garden-fresh food. 

Mustard greens are fairly easy to grow for even the most beginner-level Gardner. They’re hardy enough to survive fall and spring weather and don’t require excessively specific care for the plant. 

Are Mustard Greens Perennials? 

No, Mustard Greens are not perennial plants. Most varieties of mustard greens are annual, growing for only one season before new seeds need to be sown. 

What Are Mustard Plants?

Mustard plants are members of the Brassicaceae family, also known as the cabbage plant family. Their cousins include turnips, cabbage, and broccoli. Like cabbage, mustard plants are a vegetable variety that grows their produce above ground in the form of leaves.

The mustard plant is easily identified by its rosette patterned leaves and its yellow flowers. The iconic yellow flowers of the mustard plant are the same yellow color as the condiment that shares its name. 

Most scientists believe the cultivation and domestication of mustard began in Asia or Eastern Europe. The Indus Valley Civilization of India cultivated the mustard plant as early as 2500 B.C.E. and the plant exists in ancient Sumerian texts as a domesticated plant! 

Though its roots (pun intended!) are largely Eurasian, the mustard plant proliferates countries around the world. Wild mustard plants are found from the American wilds to the plains of China. Entire fields of wild mustard can turn the countryside yellow during its flowering season.

Wild variations of mustard plants are largely considered weeds. Mustard plants easily become “wild” when left to spread their seeds. Farmers prefer to plant late-flowering varieties to prevent the undesired spreading of the plant in later growing seasons. 

Common Traits of the Mustard Plant

Aside from the yellow flower that most mustard plant variations produce, mustard plants come with a large array of physical traits depending on the subspecies of the plant. 

  • Leaf Size

Mustard plants come in all shapes and sizes. Leaf sizes can range anywhere from ten inches to three feet long, though the average size is about fifteen inches.

  • Leaf Color

Mustard plants do not produce only green leaves. Some variations grow purple or red leaves. 

  • Leaf Shape

Mustard plants produce smooth leaves, frilled leaves, and everything in between.

  • Leaf Flavor

The leaves of mustard plants have different flavors depending on the variation. Some have a smooth, almost cabbage-like taste, while others have a sharp, peppery taste similar to a turnip or bok choy.

  • Seed Color

Different species of mustard have different colored seeds. Black mustard is typically cultivated as a spice and is identified by its black seeds. White mustard is most commonly used for making mustard condiments and is identified by its white seeds.

Uses of the Mustard Plant

The seeds, leaves, and stems of most mustard varieties are edible. Cultivators press the seeds to produce mustard oil or ground to make condiment mustard.

The mustard plant leaves are majorly popular in Asian cooking like stir-fry, but the plants have found popularity in Europe and the Americas as well. It is popular as a type of salad, as a side dish, or as a garnish, especially in Texas and the Southern United States.

Mustard plants are also used as a type of green manure, or ground cover for soils. It essentially acts as a mulch to protect soil content and moisture. Additionally, its pressed oil product has been proven an excellent, all-natural pesticide. 

Surprisingly, the mustard plant is under the gaze of scientists as a possible alternative fuel source. Biodiesel would replace the diesel products of today’s automobiles.

What is the Average Lifespan of a Mustard Plant?

Mustard plants typically live for only one growing season, usually for a period of about two to three months. The lifespan of mustard plants varies based on various factors, including climate, soil content, and water access.

In areas with early frost or colder climates, mustard plants may live for only a month or two. A surprise frost or heatwave will kill a mustard plant. In warmer climates, mustard plants can be grown all winter.

Mustard Plants vs Mustard Greens

Mustard greens are not the same thing as a mustard plant. The term “mustard plant” defines the entire plant, from roots to seeds to leaves. Mustard plants come in a variety of subtypes with their own distinctive traits. 

Mustard greens, on the other hand, are the edible leaves of a mustard plant. Surprisingly enough, not all mustard greens are actually green. The flavor, coloring, and size of mustard greens vary based on the subspecies. 

Common Mustard Plant Species

Almost every continent has a variation of the mustard plant. It is so common that some areas view the mustard plant as a weed. Common species variations of the mustard greens include:

  • Curled-leaf Mustard: This subspecies is easily identified by its curling leaf ends. Common variations include ‘Fordhook Fancy’ that has a 40-day growing cycle and the ‘Green Wave’ typically has a 45-day growing cycle.
  • Horned Mustard: This subspecies is categorically known for having a horned shape in the center of the stem. It typically has a 40-45 day growing cycle.
  • Plain Leaf Mustard: This subspecies includes the ‘Florida Broad Leaf, which has a 43-50 day growing cycle, and the Tendergreen, which has a 34-40 day growing cycle.
  • Head Mustard: This subspecies grows in a similar structure to heads of lettuce and has an average growing cycle of 40-45 days.
  • Japanese Mustard: These Asian subspecies produce giant leaves of purple color with a peppery taste. It has a 40-45 day growing cycle.
  • Korean Red Mustard: These Asian subspecies produce purplish-red leaves. It has a 45-day growing cycle.
  • Southern Giant: These subspecies produce large leaves with a mild flavor. It has a longer growing period of 50-70 days.

Do Mustard Greens Grow Back?

Mustard greens do not grow back on their own. Their limited growing season makes the mustard seed an annual plant, which means that the plant only lives for one growing season, however long that season may be. 

However, early-flowering mustard plants that produce seeds can spread the seeds for a crop to appear in the next growing season. Wild species reproduce annually thanks to the spreading of their seeds, but the parent plant will die at the end of its growing season.

How Much Sun Do Mustard Greens Require?

Mustard greens prefer full sun. Full sun requires at least 8-10 hours of direct sunlight exposure for the plant. Finding the right location can be tricky, but it’s best to plant the mustard plant in the sunniest area of the yard. 

However, because they are not fruit-bearing plants they are tolerant of a little shade. If full-sun locations are not available, mustard greens need to be planted in an area that receives as much sunlight as possible.

How Often Should I Water Mustard Greens?

You’ll want to give your mustard plants plenty of attention when it comes to watering. Expect to visit them with the watering hose at least twice a week in mild climates. In particularly dry climates, they may need daily watering, so be ready for some time in the sun for yourself, too!

If you’re unsure of how to know exactly when the plants need water, remember to water your mustard plants when the first inch of soil is dry. It’s best never to let the soil dry out, but you’ll know for sure the plant needs water when the soil has dried out.

Without consistent watering, mustard plants may produce stunted greens or die. Regular watering will help mustard plants produce their leaves quickly.

What is the Growing Season for Mustard Greens?

Mustard Greens are plants of fall and spring. They are an excellent source of vegetables in the early and late growing season when others like lettuce and broccoli are unavailable, or if you want an alternative to the traditional leafy-greens. 

Keep in mind that mustard greens are picky and prone to fits. They do not tolerate heat well, and will “bolt” or shed their seeds when temperatures start to rise. Additionally, they will die when subjected to chilly weather or early frost. 

Best Growing Methods for Mustard Greens

As previously mentioned, mustard greens are a sun-loving plant that thrives in cooler growing seasons. But, there are a ton of ways to ensure that your mustard plant grows successfully. 

Time Your Planting Right

Master gardeners recommend that mustard seeds be sown 4-6 weeks before the last frost of spring or 6-8 weeks before the first frost of fall to ensure a healthy growing window for the plant. Keep in mind that mustard plants take between 30 and 40 days to grow to their optimal size. 

If you’re planning on planting a spring crop, be aware that once temperatures reach above 75 degrees Fahrenheit, the mustard leaves will change to a bitter, spicy flavor and the plant will soon die.

Give the Mustard Plant Space

Like most headed plants, mustard plants need plenty of space to grow to prevent suffocation or over-crowding. Space your plants 12-18 inches apart. You’ll need to plant larger leaf-yielding plants 18 inches apart.

Ideal Planting Locations

After finding a suitably sunny spot to settle your mustard plant into, you’re probably wondering the best way to plant it. The good news is that as long as your mustard plant has plenty of sun and at least eight inches of soil, they’ll thrive.

This means that both raised beds, in-ground beds, and containers are excellent places to plant your mustard plant. Raised and in-garden beds will be better if you’re wanting a larger harvest of mustard, but containers will work well for smaller gardens or indoor setups. 

Plant in the Right Soil

Mustard plants prefer soil with a pH between 5.5 and 6.8. Soil should be well-worked and irrigated before you place the seeds or seedling plants in the ground. Adding compost or manure to the soil can improve the nutrient content of the soil.

Harvest the Mustard Plant Correctly

Expert gardeners and chefs alike recommend you harvest mustard greens when they are young and tender. Usually, they are harvested at the end of their ideal growing cycle. The longer the leaves grow, the more spicy and strong the flavor will become.

Common variations are best harvested when their leaves are around 6-8 inches, though giant leafed variations are harvested around 12-18 inches.

Common Threats to Mustard Plants

  • Overwatering

While mustard plants really love their water, too much can drown the plant. If water is constantly spilling over or puddling in major amounts around the plants, back off on the watering to give your mustard plant time to drink it in.

  • Disease

Mustard plants are susceptible to white rust, a disease that aflicts the leaves with a rust-like growth. Overwatering the leaves can lead to the disease. Aflicted leaves need plucked and thrown out to prevent the spread of the rust.

  • Bugs

Flea beetles and aphids love to munch on mustard leaves just as much as you do. You can wash these pests away with water and can be prevented by adding ladybugs or neem oil to the garden. 

  • Weeds

Weeds are selfish nuisances in a garden. They’ll strangle plants and swallow up the garden’s nutrients if left unchecked. Pulls weeds the moment you see them, and be sure to get their roots or they’ll just grow back again. 

Plant Companion Plants

Everyone wants friends, right? Companion plants are plants that grow well together, and using them allows you to have a more diverse garden. Mustard plants thrive with the help of companion plants, too.

Some common companion plants for the mustard plant include mint, rosemary, peas, and carrots, and corn. 

However, it’s important to know that not all plants get along with mustard. Beans are prone to mold and mildew and will encourage the unhealthy growth of the pests in the mustard plant.