SPINACH-WATER KANG KONG-ONG TSOI
SPINACH-WATER KANG KONG-ONG TSOI
A$3.50
Availability: 10 in stock
Ipomoea aquatica
SPINACH-KANG KONG-(ONG TSOI) also known as Water Spinach, is of South East Asian origin. It has long, jointed & hollow stems, which allow the vines to float on water or creep across muddy ground. Water spinach is an herbaceous aquatic or semi-aquatic perennial plant of the tropics or subtropics. Leaves are flat, and vary in shape depending on variety, from heart-shaped to long, narrow and arrow-shaped. Narrow leaves are 1-2.5 cm wide & 20-30cm long. Broad leaves are up to 5 cm wide & 15-25 cm long.
The leaves have a very pleasant, mild, sweet flavour & like many other leafy vegetables, the leaves are very nutritious, being rich in vitamins & minerals. Water spinach is not adapted to climates with mean temperatures below 10 °C & the optimal temperature is around 20C – 30C. Grows year-round in the tropics. Flowering occurs under short-day conditions and commences from mid-summer onwards. Tolerates very high rainfall, but not frost. Can be grown outside in summer. In cool areas, it can be grown in unheated greenhouses in summer, but will require heated greenhouses for a spring crop. It prefers full sun but where summer temperatures are very high, it is sometimes grown as a ground cover beneath climbing plants, sheltered from strong winds.

How to Grow Spinach-Kang Kong
- Select a suitable location for your Water Kang Kong in your garden or balcony that gets at least six hours of direct sunlight every day. They thrive in warm, humid conditions and require plenty of sunlight.
- Water Kang Kong prefers moist, fertile soil on raised beds 60-100 cm wide. If your soil is heavy and compacted, add some organic matter such as compost or well-rotted manure to improve its texture and fertility.
- Seeds are sown directly into the soil at a depth of about 1 cm (0.4 in). Or nursery-grown seedlings are transplanted into the beds. Space the seeds about 10 cm (4 in) apart to allow for growth. Water the seeds well and keep the soil moist until the seeds germinate, which usually takes about 7-10 days. Seeds should be no more than 2 years old and can be soaked for 24 hours before sowing to encourage germination.
- To produce strong seedlings, seed should be sown 5-10 mm deep in trays with potting mix deep enough to allow the plants to develop a good root system. Transplanting should take place when plants are 10-15 cm high, with four true leaves. Highest yields are obtained by spacing plants at 15 x 15 cm.
- Water spinach can also be raised from stem cuttings, 30-40 cm long, taken from the young growth just below a node, and planted about 15 cm deep. To ensure earliness, growers in China sometimes lift roots at the end of the season, store them carefully in winter, and plant shoots from them in spring.
- When rainfall is low, frequent heavy irrigations are necessary for high quality shoots
- Once your Water Kang Kong plants have grown to about 10 cm (4 in) tall, thin them out to a spacing of about 20-25 cm (8-10 in) apart. This will give the plants enough room to grow and produce lots of tasty leaves.
- Water Kang Kong grows best in temperatures between 20-30°C (68-86°F). It is important to keep the soil consistently moist throughout the growing season, as Water Kang Kong does not tolerate dry conditions.
Heritage of Kang Kong Spinach (ong tsoi)
Also known as water spinach or swamp cabbage, Kang Kong Spinach has its origins in Southeast Asia, particularly in countries like China and Vietnam. It has been cultivated for centuries in these regions and is a staple in many Asian cuisines. Kang Kong is known for its fast growth and adaptability to wet, waterlogged conditions, which is why it’s often found in flooded fields and along the edges of bodies of water.
It is widely used in stir-fries, soups, and salads, and its tender shoots and leaves are prized for their mild, slightly peppery flavor. Kang Kong has become popular in other parts of the world as well due to its nutritional value and ease of cultivation.
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Category Colour Guide
Planting Guide for Australia
Scoville Heat Units (SHU)
Plant Height
20-30 cm (8-12 inches)
Season of Interest
Spring, Summer, Autumn
Temperature Range
18-32°C (65-90°F)
Determine / Indeterminate
Annual / Perennial / Biennial
Annual
Frost Hardy / Tender
Tender
Full Sun / Part Sun / Shade
Full sun to part shade
Sow Direct / Raise Seedlings
Sow direct or grow from cuttings
Soil
Well-draining soil rich in organic matter
pH
6.0-7.0
Soil Temperature
20-32°C (68-90°F)
Seed Preparation
Soak seeds in warm water for 24 hours before sowing
Sowing Depth
1 cm (0.4 inches)
Plant Spacing
15-30 cm (6-12 inches)
Row spacing
30-45 cm (12-18 inches)
Watering
Keep the soil consistently moist
Germination Time (Days)
7-14 days
Harvest Time (Days)
30-60 days - harvest leaves when they are young and tender
Good Companion Plants
Basil, Nasturtiums, Marigolds, Chives
Bad Companion Plants
Brassicas, Potatoes, Onions
Pests
Aphids, Caterpillars, Slugs and Snails
Diseases
Downy Mildew, Powdery Mildew, Leaf Spot
More About Us
When I started this journey in 2009, I found nothing existed commercially, that was reasonably priced and easy to use. There was a homemade system which I also found was not that user-friendly.
Then a friend of mine told me about a homemade method she used. However, when I tried her method, I found this also didn’t suit my needs, as it too had flaws that I considered where important. It did not keep vermin out, did not have a lockable lid and (to me) looked unsightly in the garden