How to grow Kang Kong (Water Spinach) in Australia
Kangkong, or water spinach (Ipomoea aquatica), is a fast, leafy tropical green with hollow stems and mild, tender leaves that are never bitter. It loves heat and very wet soil, and can even be grown floating in a tub of water. In the tropics it can be picked all year; further south it is a summer crop only.
📖 Our full guide: How to Grow Kangkong (Water Spinach) in Australia
At a glance
When to sow by region
| Region | When to sow | Regional note |
|---|---|---|
| South East Queensland | September to March | |
| Northern Rivers NSW | September to March | |
| Sydney & Coastal NSW | November to February | Marginal tropical; shorter viable window than SEQ; needs sheltered warm site. |
| Melbourne & Victoria | Not suited | Not viable in Melbourne. Kangkong needs at least 15°C, and the frosts from May to September kill the plant. |
| Adelaide & SA | Not suited | Mediterranean: unsuitable. Kang Kong (water spinach) tropical; requires year-round warmth. Not viable Adelaide/Perth. |
| Perth & WA | November to February | Marginal coastal at best: needs a permanently wet frost free corner through summer. Sow Nov to Feb in warm wet spots; most Perth gardeners do better buying it. |
| Tasmania | Not suited | Unsuitable. Tropical water green needing 20C plus. Not viable in Tasmania. |
| Canberra & ACT | Not suited | Kang Kong unsuitable for Canberra: tropical vine; frost kills it. Use silverbeet or amaranth instead. |
| North Queensland | September to March | Wet season staple Sep to Mar. Kangkong is tropical leafy green heartland crop. Grows year-round; thrives in humidity. |
| Darwin & Top End | September to March | Wet season staple Sep to Mar. Kangkong is tropical leafy green heartland crop. Grows year-round; thrives in humidity. |
Not to be confused with: Sweet potato, a close relative in the same genus grown for its tubers, and Brazilian spinach, another tropical green.
Where to plant
Grow kangkong in full sun in rich soil that stays very damp, such as a low, wet corner of the garden, the edge of a pond, or a container of water. It needs warmth and steady moisture and stops growing in cool weather.
Kangkong spreads quickly by its trailing, rooting stems. Keep it in a contained bed or tub, and never put cuttings or plants into creeks, dams or other natural waterways.
- North Queensland and Darwin: a wet season staple from September to March, and it keeps growing year round in the tropics.
- South East Queensland and the Northern Rivers: plant from September to March, in a wet spot or a tub of water.
- Sydney and Perth: marginal. Plant from November to February in a warm, sheltered, permanently wet spot. In Perth it needs a frost-free corner kept wet all summer.
- Melbourne, Adelaide, Canberra and Hobart: our calendar marks these as unsuitable, as it needs warmth and frost kills it. Grow silverbeet or amaranth instead.
How to plant
- Kangkong is easiest from cuttings. Use stems from a plant or from a bunch bought at an Asian grocer, choosing thicker stems with a few leaves.
- In the garden, push the cuttings into rich, wet soil about 20 cm apart, or sow seed shallowly in warm, moist soil.
- To grow it in water, fill a large tub with water, place a grid of mesh or tied bamboo just below the surface, and lay the cuttings on it with the leaves above the water. Thicker stems float better.
- Keep the soil wet, or the water topped up, while the cuttings root, which takes only days in warm weather.
Watering and feeding
Never let kangkong dry out. In the ground, water generously every day in hot weather, or grow it where the soil stays wet. In a tub, keep the water topped up.
Kangkong is hungry and needs plenty of nutrients to keep growing fast. Feed often with a liquid fertiliser high in nitrogen. In a tub, Gardening Australia's Leonie Norrington adds a liquid made from chook or cow manure steeped in water, which the roots take up straight from the water. If you keep fish in the tub, use a weaker feed.
Pruning and care through the year
- Pinch out the tips regularly to keep plants bushy and full of new shoots.
- Standing water breeds mosquitoes. Use a container that overflows often, such as one under a tap, or add a few small fish to eat the larvae.
- Choose a container small enough to reach across, so you can harvest easily and check every leaf for pests.
Harvesting
Start picking about six weeks after planting. Cut the top 15 to 20 cm of each stem, with its leaves, and the plant sends out new shoots from below the cut. Harvest every few weeks through the warm months. Young, tender tips are best.
Kangkong wilts quickly once cut. Use it the same day, or keep it in a bag in the fridge for a day or two.
Growing in pots
Kangkong grows well in containers: either floating in a large tub of water on a mesh grid, or in a pot at least 25 cm wide of rich potting mix stood in a saucer of water so it never dries out. Container growing suits small gardens and balconies and means no weeding.
Using it
Stir-fry kangkong quickly with garlic, chilli and fermented bean or shrimp paste, as in many Southeast Asian dishes, or add it to soups. The hollow stems stay crunchy and the leaves wilt quickly. Young tips can also go into salads.
Varieties
- Land Kangkong (Upland)
Pests and diseases
Kangkong has few serious problems. Check leaves regularly, especially on plants grown in tubs.
Pests to watch for
- Leaf miner Pale, winding trails inside the leaves. Pick off affected leaves.
- Caterpillars Holes chewed in the leaves. Pick caterpillars off by hand.
Diseases to watch for
- White rust White, blister-like pustules under the leaves and on stems, with yellow patches above, often in humid weather. Remove affected shoots and avoid crowding.
Common questions
Can I grow kangkong from supermarket bunches?
Yes. Stems from a fresh bunch bought at an Asian grocer root easily. Use the thicker stems with a few leaves, and push them into wet soil or float them in a tub of water.
How do I grow kangkong in water?
Fill a large tub with water, set a mesh or bamboo grid just under the surface, and lay cuttings on it with the leaves above water. Feed the water with liquid manure, and keep mosquitoes down with an overflowing tap or a few fish.
How often can I harvest kangkong?
Every few weeks through the warm months, from about six weeks after planting. Cut the top 15 to 20 cm of each stem and it regrows from below the cut.
Can I grow kangkong in Sydney or Melbourne?
In Sydney, only as a summer crop in a warm, wet spot. Melbourne is too cold, as kangkong needs warmth and frost kills it.
Does kangkong need full sun?
Yes, it grows fastest in full sun with constantly wet soil or water and warm temperatures.
Is kangkong the same as water spinach?
Yes. Kangkong, water spinach and water morning glory are names for Ipomoea aquatica, a relative of sweet potato.
Sources we checked: Gardening Australia: Growing kangkong (Leonie Norrington, Darwin).