How to Grow Mouth-Tingling Mustard Greens (and Seeds)

At nearly every fast food restaurant, hot dog stand, and backyard cookout, you’ll find a ubiquitous yellow bottle. Stored inside is a sweet-spicy condiment —ketchup’s trusted sidekick — made with seeds of the mustard plant.

But the crop is useful for more than just its seeds.

One cup of mustard greens boasts 500% of your daily value of vitamin K — which supports cardiovascular health and reduces inflammation — as well as high doses of vitamins A, C, and E, fiber, manganese, and more. (Mustard belongs to the Brassicaceae family, along with broccoli, brussels sprouts, and cabbage, practically making it a superfood by default.)

Besides offering an array of health benefits, mustard adds a unique zing to salads, stir-fries, and other dishes. And in this guide, you’ll learn how easy it is to grow with Tower Garden.

Choosing a Which Type of Mustard to Grow

Though most Asian greens, such as bok choy and mizuna, are technically mustards, the species that actually carry the name “mustard” include:

  • Black mustard (Brassica nigra) – Though its leaves are edible, B. nigra is usually grown for its seeds, which serve as the foundation of many moderately spicy mustards, including Dijon.
  • White mustard (Brassica alba) – The mildest option, B. alba yields seeds that are perfect for mustards and preserved produce (e.g., pickles, relishes, chutneys).
  • Brown mustard (Brassica juncea) – This one’s got a wasabi-like bite. Many curries and hot mustards contain the spicy greens and seeds of B. juncea.

You can’t go wrong with any of the options above. But if you’re not sure which to choose, we recommend starting with brown mustard varieties. They’re great for both seed and green production. (Opt for the “Red Giant” variety to add a bit of visual appeal to your garden.)

When to Plant Mustard Greens

Considered a cool-season crop — one that can even withstand light frosts — mustard grows best in the spring and fall.

If you’re growing mustard for its seeds, planting in the spring is ideal because the higher temperatures that come with summer trigger bolting and seed production. Conversely, planting around this time of year (i.e., late summer, leading into fall) is often better for the production of greens. Of course, you can also grow mustard any time of year indoors.

Start by planting about six seeds per rockwool cube. Mustard is very easy to germinate. In fact, under the right conditions, it may sprout in just one or two days. As soon as it does, give it lots of light to prevent weak, leggy growth.

Recommended: How to Grow Strong, Healthy Seedlings in 7 Steps »

Growing Mustard Greens

Once your seedlings are about three inches tall and have roots protruding from the rockwool cube, they’re ready to transplant.

Keep in mind that, though it prefers full sun, mustard will tolerate some shade. You can transplant mustard anywhere in your Tower Garden, including into the Micro Greens Extension Kit if you’d like to grow it as a colorful, zippy garnish.

After you’ve transplanted your mustard seedlings, you can sit back and relax — it’s a carefree crop to grow. Even pests tend to leave it alone. (But for good measure here are a few pest prevention best practices.)

Harvesting Mustard Greens and Seeds

Mustard greens grow quickly and can be ready to harvest in as few as 40 days. The most popular harvesting approach is known as the come-again-cut-again method. It’s called that because the technique allows the plant to keep growing and produce additional yields for months.

Here’s how it works:

  • With a sharp knife or scissors, cut the bottommost, older leaves
  • Take care to not damage the inner leaf tips
  • Allow at least 2/3 of the foliage to remain
  • Frequently return to harvest more and encourage new growth

If you’re growing the crop for seeds, the planting-to-harvest timeline will be a little longer. (To expedite the process, don’t harvest any greens.) But first you’ll see yellow or white flowers. Within a few days, those will give way to small green pods. Wait for these pods to dry, as indicated by browning. Once they do, you can either rub them between your palms or shake them inside a paper bag to release the seeds.

Fair warning: mustard yields a lot of tiny seeds.

How to Use Mustard Greens and Seeds

Young, raw mustard greens add a delightfully sharp tang in salads. But as the crop matures, most people prefer to cook (e.g., sauté, stir-fry) it because the larger leaves can be quite potent and tough.

Not sure what to do with the seeds? Try adding them to a dish that could use a little extra kick — such as an Indian curry — or mix them with a few other simple ingredients to create the popular condiment that borrows the plant’s name. (You can also save the seeds to grow next year’s crop.)


We hope this guide helps you grow the most amazing mustard you’ve ever tasted. (Or, at the very least, causes you to think of the condiment a little differently!)

If you have any questions or comments, we’d love to hear from you below.

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