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How to Grow Tatsoi (Spoon Mustard)

Caren White is a Master Gardener and instructor at Home Gardeners School. She has been associated with Rutgers Gardens for over a decade.

how-to-grow-tatsoi-spoon-mustard

I love spicy foods. That includes spicy greens in my salads. Tatsoi has a tangy mustard flavor that can spice up an otherwise bland salad.

What is Tatsoi?

Tatsoi (Brassica rapa subsp. Narinosa) is an Asian green that is native to China. It is related to bok choy and napa cabbage. Tatsoi is a biennial in growing zones 4 – 7. If planted in the fall, it will overwinter with protection and resume growth in the spring. The plants will bolt (flower and set seed) as warm summer weather sets in.

Unlike bok choi and napa cabbage which grow in upright oval heads, tatsoi grows in a flattened head that can be 8 to 10 inches tall and 12 inches wide. The leaves are dark green and spoon shaped, hence its nickname Spoon Mustard. Leaves that are harvested when they are young and small taste like spinach. Mature leaves have a tangy mustard flavor. You can use them any way that you use bok choi or napa cabbage. Tatsoi leaves are most frequently used raw in salads or cooked in soups and stir fries.

Tasoi grows in a flat head.

Tasoi grows in a flat head.

How to Grow Tatsoi

Like its cousins, tatsoi prefers partial shade. It only needs 3 to 5 hours of sunlight daily. You can grow it in full sun if you keep it well-watered. If the plants start to dry out, they will bolt, i.e. flower and then set seed.

Soil is critical. Tatsoi wants rich, well-draining soil. If you have predominantly clay or sandy soil, you should probably grow it in raised beds or containers. If you have loamy soil, you will want to enrich it with lots of compost. You should also test the pH in your soil. The ideal pH range for this plant is 6.5 – 7.0.

Make sure that you don’t allow your plants to dry out. This will cause them to bolt. Keep them well-watered. A thick layer of mulch will help your soil retain moisture and prevent weeds from growing and competing with your tatsoi for water.

Apply fertilizer several times during the brief growing season. A fish emulsion fertilizer is recommended, but you can also use any high nitrogen fertilizer such as 20-20-20. Nitrogen promotes foliage growth and you are growing tatsoi for its leaves.

How to Grow Tatsoi From Seed in the Spring

Start Seed Outdoors – you can sow your seeds outdoors after your last frost. Plant them ¼ inch deep and 2 -3 inches apart in rows that are 8 – 12 inches apart. They will germinate quickly, usually within 4 – 8 days. When your seedlings are 3 inches tall, thin them to 6 to 8 inches apart. You can eat the thinnings in your favorite salad.

Start Seed Indoors - you can start your seeds indoors 4 to 5 weeks before your last frost date. Plant them ¼ inch deep. They will germinate just as quickly indoors, 4 – 8 days. You can transplant your seedlings outdoors into your garden when they reach 3 inches tall and after your last frost. Space them 6 to 8 inches apart.

How to Grow Tatsoi From Seed in the Fall

You can sow seeds in late summer for a fall harvest. In my NJ zone 6 garden, I sow my cool season crops in August. Sow your seeds ¼ inch deep and 2 -3 inches apart in rows that are 8 – 12 inches apart. They will germinate quickly, within 4– 8 days. When your seedlings are 3 inches tall, you can thin them to 6 to 8 inches apart. You can eat the thinnings if you like. I like to add them to my salads.

How to Harvest Tatsoi

Your tatsoi will be ready to harvest in 40 to 50 days. To harvest, take a sharp knife and slice the head off one inch from the ground. As long as the weather is not too hot (spring/summer) or too cold (fall/winter), the plants should resprout for a cut and come again harvest. The second heads will be smaller than the first ones, but just as delicious.

How to Store Tatsoi

Freshly harvested tatsoi can be stored in your refrigerator for 3 to 5 days. Store the heads, unwashed, in plastic bags. Don’t wash the leaves until you are ready to use them. If you try to wash them and then store them in plastic bags, the leaves will rot.

© 2020 Caren White