Red Tatsoi Mustard

Tatsoi grows best in fertile, well-draining soil with a pH between 6.0 and 7.5 and requires full sun to partial shade. It is a cool-season crop that can tolerate some heat but grows best in temperatures between 45-75°F. Tatsoi has a relatively short growing season and can be harvested as soon as 35-45 days after planting. The soil should be kept consistently moist but not waterlogged, and the plant may benefit from occasional fertilization. Tatsoi is a versatile plant that can be grown in both traditional garden beds and containers.

Sow seeds outdoors as soon as soil can be worked.  Plant seeds 1/4" deep, 1" apart in rows 18" apart.  Germination will occur in 7-14 days.  Once seedlings have emerged, thin to one plant every 3-6".  Successive fall plantings can be made beginning six weeks before first frost.

Not recommended. Plants grown indoors are prone to bolting.

Insect Pests

While rarely a serious issue, tatsoi mustard is susceptible to insect pests such as aphids, flea beetles, and caterpillars. Flea beetles can cause small holes in the leaves, while aphids can distort and yellow the leaves. Caterpillars, particularly the diamondback moth caterpillar, can cause significant damage by eating large sections of leaves. To prevent and manage insect infestations, it is recommended to use row covers, crop rotation, and natural predators such as ladybugs and lacewings. In severe cases, insecticidal soap or neem oil can be used as a last resort.

Diseases & Other Problems

Although not common, tatsoi mustard can be affected by diseases such as black rot, clubroot, and downy mildew, which can cause stunted growth, yellowing leaves, and wilting. To prevent these diseases, it is recommended to use disease-resistant varieties, practice crop rotation, and avoid planting in wet or waterlogged soils. Additionally, overwatering or overcrowding can lead to fungal diseases such as damping-off, which can cause seedlings to wilt and die. To prevent damping-off, ensure proper drainage and provide good air circulation. Bolting is common in periods of high temperatures. Providing some shade can somewhat delay the onset of flowering.

Tatsoi can be harvested as soon as the leaves are large enough to eat, typically 35-45 days after planting. The entire plant can be harvested by cutting it near the soil surface, or individual leaves can be picked as needed. The leaves can be eaten fresh or stored in a plastic bag in the refrigerator for up to a week. Tatsoi can also be blanched and frozen for longer storage. To blanch, briefly boil the leaves in water, then rinse with cold water and freeze in airtight containers or plastic bags.

CONSIDERATIONS:

Tatsoi mustard is an outcrossing plant with pollination primarily being performed by bees and other insects. To maintain varietal purity, isolate at least one-quarter mile from all plants of the Brassica rapa species. This class includes mustard, turnip, rutabaga, pak choi and some wild plants. If isolation by distance cannot be guaranteed, cover plants with netting or other physical barriers (pollinators will need to be introduced in this scenario).

HARVESTING SEED:

After flowering, the seed heads should be left on the plant until they have dried and turned brown. Cut the seed heads and lay flat on a tarp until completely dried. Once the siliques have dried, place stalks in a bag and stomp on them to release the seed. Winnow to separate the seed from the chaff and store seeds in an airtight container.

SEED LONGETIVITY:

Tatsoi seeds can maintain their viability for 3-5 years if stored properly. To ensure the longest possible viability, store the seeds in a cool, dry place in an airtight container or envelope.