Hon tsai tai, also known as kosaitai, is a stunningly beautiful and delicious Asian vegetable.
It adds vivid color to an array of dishes and delicious tastes and textures. It’s not easy to find it outside of authentic Asian markets, and it’s best enjoyed fresh.
Fortunately, in this guide, we’ll show you just how easy it is to grow hon tsai tai at home.
What is hon tsai tai?
Hon tsai tai is a species of Chinese flowering cabbage from the Brassicaceae family. It is very closely related to yu choy, and you will often find it under the common name of purple choy sum.
What makes this vegetable genuinely unique is the stems’ color, ranging from red to dark purple. Paired with the vivid yellow flowers, it can make a stunning addition to any meal — both visually and in terms of flavor.
Hon tsai tai can grow up to 12 inches (30 cm) tall, producing dark green leaves and thin, purple stems. Its stems are quite similar to those of young purple broccoli and have a mild, sweet flavor. It is best grown as a cold season crop, and given its low maintenance, it deserves a spot in your garden.
How to grow hon tsai tai
You can quickly grow hon tsai tai in your garden all year round if you live in a mild climate. You can harvest this cold season crop in as little as 40 days after sowing. This period means you can plant it several times each year. There’s no better way to enjoy a fresh supply of this delicious veg.
Here’s what you need to know to get started on your hon tsai tai cultivation.
Growing hon tsai tai outdoors
When should you plant hon tsai tai? You have two options: in spring or early summer. The trick is to make sure that temperatures don’t exceed 77 °F (25 °C). Hon tsai tai prefers growing in cool weather, which will stimulate abundant growth. Temperatures around 57 °F (14 °C) will also give the stems a sweeter taste and deepen their purple color.
We suggest sowing hon tsai tai in June and harvesting it in early or mid-autumn for best results. If you’re planning spring sowing, you can germinate the seeds indoors and transplant them to your garden once temperatures remain steady above 50 °F (10 °C).
However, it’s best to note that any drop below that temperature range will cause your hon tsai tai plants to bolt, producing flowers and seeds prematurely.
Hon tsai tai grows best in rich, well-draining soils, with a pH ranging from 6.0 to 7.0.
Before sowing, take the time to prepare the soil by incorporating compost into the substrate. This way, you will create a nutrient-rich substrate that will provide your plants with all the minerals they need to grow. You won’t have to worry about applying fertilizers later on.
Hon tsai tai needs at least 6 hours of sunlight for optimal growth. If you’re in a pinch for space in your garden, you can also plant it in partial shade, especially if you’re growing hon tsai tai as a summer crop. This way, you will protect it from the summer sun’s intense heat, which can give the stems a slightly bitter flavor.
Hon tsai tai seeds are small and easy to work with and don’t require soaking before you sow them. They need a temperature range of 65 °F to 75 °F (18 °C to 24 °C) to germinate, and the hon tsai tai seedlings will pop out after about 7 days.
Let’s take a quick look at how to sow them, depending on the time of the year:
- For spring crops: start by sowing the hon tsai tai seeds in compostable seedling pots. A 2 inch (5 cm) pot should be more than enough. Fill it with potting mix, place one seed in each pot, and cover with a thin layer of soil. Use a spray bottle to mist the soil, keeping it moist but not soggy. Once the first seedlings appear, wait until each plant has at least 2 sets of leaves before transplanting to your garden. By this point, outdoor temperatures should also stay above 50 °F (10 °C) to prevent bolting.
- For summer crops: you can sow your hon tsai tai seeds directly in the soil. Using your finger, poke a hole in the soil that’s around 0.2 inches (half a centimeter) deep, place the seed inside, and cover with soil. Hon tsai tai seed spacing should be about 2 inches (5 cm) and thin the plants further as they mature, usually to 8 inches (20 cm) apart.
When hon tsai tai plants are young, they will need thorough watering, especially in the first two weeks after being sown. As the plants become settled and mature, you can reduce the watering but avoid extended periods of drought.
Too little water will stress the plant, causing it to bolt and become bitter, yet too much can encourage fungal diseases. Find the perfect spot by keeping the soil moist, but avoid overwatering.
Hon tsai tai has few diseases. But like most plants in the cabbage family, it’s a delicious snack for pests such as snails, slugs, caterpillars, or the leafminer bug. The easiest and safest way to stay on top of your pesky visitors is to check your hon tsai tai daily. Remove snails or caterpillars by hand, and throw them in a bucket of soapy water.
For fungal diseases such as powdery mildew, our tip is to spray your hon tsai tai plants with a solution of water and baking soda. Unless you’re planning on harvesting them when they’re very young, avoid planting hon tsai tai too close together. It will create poor air circulation, which is essentially inviting fungal problems into your garden when paired with watering too frequently.
When to harvest hon tsai tai
Hon tsai tai is a fast-growing and versatile crop that can be harvested at any point once the plants have become established.
You can harvest the baby leaf to use hon tsai tai greens when the plants are only 4 inches (10 cm) tall. Stems and flowers should wait until plants are around 12 inches (30 cm) tall. Use the cut-and-come-again method to get the most out of your crop. You can do this by trimming the stalks from the center of the plant. It will encourage new growth, which will also result in sweeter, tender stems.
Harvesting hon tsai tai seeds
If you want to collect seeds from hon tsai tai, wait until the plant reaches at least 16 inches (40 cm) in height, and the yellow flowers start blooming.
After the flowers have wilted, they will produce long, thin seed pods. Leave the pods on the plant until they are completely dry, as picking them when they’re still green will not result in any viable seeds.
Once the pods are dry, cut them off the plant, and store them in a paper bag for a couple of weeks. You can then break open the pods and store the small seeds until next year. A single hon tsai tai plant can quickly produce around 100 seeds.
It’s best to note that allowing your hon tsai tai to flower and produce seeds will make the stems bitter, pungent, and stringy. You can still harvest the leaves at this point, but their flavor won’t be as fresh as in younger plants.
Cooking with hon tsai tai
Hon tsai tai is a wonderful vegetable to cook with, providing a feast for the eyes as well as the taste buds. It has a mild, sweet flavor similar to spinach and broccoli, while the flowers have a mustard bite hint. The purple stems retain their color when cooked and have a crunchy but tender texture.
All parts of hon tsai tai are edible, and you can enjoy every aspect, both cooked or raw.
The best way to enjoy this vegetable is when it’s freshly picked from your garden. To preserve the most of its aroma and texture, stir-fry it with garlic, soy sauce, and a dash of sesame oil. It will be a real treat! Hon tsai tai stems can be cooked the same way as broccoli or kale, while you can prepare the like spinach.
What can you substitute hon tsai tai with?
Hon tsai tai and choy sum have a very delicate flavor, so finding an exact substitute for their unique aroma can be tricky. Gai lan is one of the closest matches, especially if you’re preparing an Asian-style recipe. Young purple broccoli stems will also work as a treat. So will broccolini, given their tender texture and mild sweetness. For hon tsai tai leaves, try using kale, rapini, or even spinach instead.
Hon tsai tai is one of our favorite Asian veggies to grow and eat, and with this guide, you too can enjoy its numerous delights.
Let’s go over some of the basics;
- Sometimes known as hon tsai tai flowering broccoli, it comes from the same family. It shares many attributes with its western counterpart.
- Hon tsai tai can be grown year-round in mild climates, ensuring a bountiful supply of deliciously fresh veg.
- It’s a fast grower and can typically be harvested within 40 days or so from sowing.
- If you’re planning to grow hon tsai tai broccoli in spring, it’s best to germinate the seeds indoors before transplanting them outside.
- When you harvest hon tsai tai, you can use the cut and come-again method to ensure a greater yield.
It is as easy as that to grow this stunning vegetable at home, so what are you waiting for?