So, you want to grow kangkong from scraps or seeds at home.
This delicious water spinach is a juicy, nutritious, versatile leafy that can be used in a variety of dishes.
Popular in Southeast Asian countries, kangkong (water spinach) is easy to grow and can be harvested for a year-round supply of greens.
We’ll find out how to grow this tasty spinach with ease so you can enjoy the “fruits” of your labor in a bunch of Asian dishes like adobo or stir-fry.
Let’s dive in and find out how to grow this spinach.
Guide Contents
Quick care guide: Kangkong (water spinach)
| Plant type | Perennial (zones 8-15), annual (zones 5-7) |
| Origin | Southeast Asia |
| Scientific name | Ipomoea aquatica |
| Other names | Water spinach, river spinach, water cabbage, water morning glory, Chinese watercress, Chinese water spinach, swamp cabbage, ong choy |
| Soil type | Loamy, well-draining, nutrient-rich |
| Soil pH | 6-7 (slightly acidic) |
| Sunlight requirement | Full sun |
| Bloom season | Spring, summer |
| Colors | Green, yellow, pink, white |
| Max height | 12 inches |
| Max width | 3-4 inches |
| Low temperature | 50F |
| High temperature | 90F |
| Ideal temperature range | 68-86F |
| Humidity | High |
| Watering requirements | Often, when the top layer (1 inch) of soil goes dry |
| Fertilizer requirements | Low |
| Fertilizer NPK | 15-15-15 |
| Days until germination | 2-3 weeks |
| Days until bloom | 40-60 days |
| Speed of growth | Very fast |
| Hardiness zones | 8, 9, 10, 11, 12, 13, 14, 15 |
| Plant depth | 0.5-1 inch |
| Plant spacing | 3 inches |
| Propagation | Seeds, stalks, cuttings |
| Common pests | Leaf beetles, aphids, wireworms, gnats, spider mites, locusts, stink bugs |
| Common diseases | Fungus, leaf spot, root rot |
| Indoor plant | Yes, but not optimal |
| Outdoor plant | Yes |
| Grown in container | Yes |
| Flowering plant | Yes |
| Beginner friendly | Yes |
| Care level | Very low (easy) |
| Uses | Edible, recipes, food, vegetable, aquatic decoration, pond decoration |
What’s kangkong?
Kangkong, also known as water spinach, is a vegetable plant that’s used in Asian dishes. It’s not as popular here in the US, but it can be grown very easily just like any other leafy green.
Similar to bok choy, garlic, or celery, you can grow it from cuttings and regrow it over and over so you never have to buy it again.
The seeds may need to be specially ordered because you won’t find them locally unless you have a nursery that specializes in exotics.
Water spinach has fine green leaves with hollow stems. This leads them to float easily on the water. Since both parts are completely edible, this allows kangkong to be used in a variety of dishes.
Origins
Kangkong originates from Southeast Asia and India in swampy, pond-like, or marshy areas. It’s a semi-aquatic plant that’s considered to be highly invasive as a weed.
So you must check with your local regulations before planting.
What does kangkong taste like?
Water spinach is similar to regular traditional spinach, with a slightly bitter and nutty taste.
The texture is also largely the same. It can be used as a substitute for spinach in dishes that call for it if you want something a little different.
Check local regulations before you plant
Note that water spinach is considered to be illegal in some areas because it’s considered to be a weed.
So you’ll need to make sure that it’s OK to grow in your area before you plant.
Hardiness zone
Kangkong grows in zones 10-11 and prefers warmer climates. It’s found in swampy areas or ponds in Southeast Asia. If you grow it in a colder zone, it can be grown indoors.
Water spinach can also be grown in zones as low as 5, 6, 7, and 8 and higher zones such as 12, 13, and 14. Some people have had success in zone 15.
Or you can grow it outdoors in the garden as an annual plant.
How to plant kangkong
There are many different ways to grow water spinach, but most of them require that you start out using a small vessel of water to germinate it.
We’ll start with the various methods you can use to start your sprouts.
Propagating kangkong
There are different ways to propagate kangkong- from cuttings, in water, and from seed. We’ll cover the various methods you can use depending on how you source your plant.
Starting from cuttings
Starting with cuttings or scraps is my preferred method because it’s a lot faster for those that are not patient. You can see results quickly using an established plant that’s already cut.
The cuttings taken from another grown plant will root when successfully transplanted.
Use sterile pruners to avoid introducing bacteria into the newly cut wound. Cut at least 3” of foliage. Then put them into clean water with their stem facing into the water.
Continue to watch for any fungal problems. The roots should develop in a few days. Wait around 10 days to transplant into soil. If the water gets dirty, replace it. Keep it out of sunlight during this time when it roots.
Planting water spinach scarps is easy.
This is the method people refer to when they say they want to grow Kangkong in water. The cutting just floats in the water until it roots.
Planting from seeds
Starting from seed is the most common way people get started. This is the slowest method, but it’s accessible for people looking into growing kangkong.
Because kangkong is hard to find, people buy the seeds and need to germinate them on their own.
Start by dumping out the packet of seeds and place them all into a small bowl of water. You only need an inch or so. No need to overdo it.
Start with a good dozen or so because they won’t all germinate. Let it soak for 24 hours and don’t disturb them. Keep them out of sunlight during this period and let them be. The water preps them to germinate. You can get the next few steps done while you wait.
Use a starter tray to begin the process. You can buy those cheap 24 or 36 tray plastic trays and use a dome to cover them. If you want to go DIY style, you can use egg crates.
Stick the seeds into each compartment. You can put 2-3 seeds evenly spaced in each square. Plant the seeds around 0.5″ in depth. Use the right soil for the best results. Space 3 inches apart. Utilize row planting for yield.
Backfill with soil. No need to use a topper or mulch if you’re in a warmer zone.
Add some water and keep the humidity high by covering the seed tray with a plastic dome. It should fog up. When the seedlings sprout, remove the dome.
Let them grow with a regular watering schedule and proper sunlight. They’re ready to transplant when they reach around 5” in length. They should have at least 4 leaves so they can gather sunlight and photosynthesis properly.
Transplanting
When your seedlings are tall enough or when your cuttings were grown in water take root, it’s time to move your kangkong into your garden. Here’s how.
First, the best time to plant is in the early summer.
You want the temperatures to be stable and no cold snaps to happen overnight. Temps should be above 50F at night and the daytime temps should be around 80F.
This plant likes warmer climates for optimal growth, so make sure you check the forecast before you plant. Or else you could kill your seedling. This is usually several weeks after the last frost date in your hardiness zone.
Cold weather will kill kangkong.
Use a small garden spade and dig up a hole that’s about 3 inches deep and less than 1 inch wide. The plot should be just big enough for your seedlings or cuttings, depending on whichever method you used to divide your plant.
Place the plant into the hold gently and backfill around it with good quality soil.
Space kangkong plants at least 6 inches apart. They like their space and this will reduce competition for soil nutrients of each plant can reach their optimal size. Don’t compress. This may compact the soil and decrease the drainage efficiency.
After you’ve planted all of your water spinach, water it generously for the first time. They soak up water quickly and will need a lot to thrive.
Since they’re a warm-weather plant, they need plenty of water to grow quickly and produce those lush green leaves. Make sure you use well-draining soil so the water doesn’t get waterlogged.
If you’re growing in a container, there’s a section for that later.
Row planting
An efficient way to grow a lot of kangkong at once is to plant them in rows. If you have a tiny garden, row planting can save you space while maximizing your crop yield.
Space each row about 8” apart with 10 seeds per row. This will make watering them en masse a lot easier and can be set up for drip irrigation.
Soil type
Water spinach grows in soil that’s rich in organic content with high humidity and moisture. These types of soils are generally sold as “clay” soils. Keep the pH around 6-7.
Add organic compost to help enrich the soil. The soil should be fertile, well-draining, damp, moist, and soft. This vegetable eats up nutrients quickly from the soil like no other to help spur its green leaves.
So make sure you supply it with everything it needs to help get the best possible harvest.
Watering
Water generously the first few times you plant. If you’re growing from cuttings, it can be planted directly in water.
Otherwise, planting in the soil can be done if the soil is well-draining.
Water plenty the first week or so to allow water pathways to establish. If you see any water getting stuck and pooling, you need to till the soil or replace it with a well draining one.
After the first week, water every 2 days when the top inch is nearly dry.
Water spinach is a thirsty plant so don’t let it go dry. It natively grows near ponds and water sources, so keep it quenched- don’t let it go dry!
Kangkong likes swampy or pond-like substrate, so almost muddy soil does well. You should be more worried about underwatering than overwatering. They call it water spinach for nothing.
Keep the pH slightly acidic to natural (ph 6-7).
Sunlight
Provide plenty of direct, full sun for best growth. It can grow in shade, but it prefers full sun. Kangkong requires full sun to produce those gorgeous green leaves.
Humidity
Keep the humidity high (above 50%) when possible.
Kangkong is natively grown in swampy conditions so the humidity is always high. The sun evaporates the water constantly and raises the humidity.
Temperature
Kangkong is a tropical plant so it prefers warm temperatures.
Keep nighttime temperatures above 50F and daytime below 80F. When it’s still germinating, 70F is a good range. Plant in early summer or late spring.
Plant food
Fertilizer isn’t necessary when grown in the soil.
But if you’re planting in a container or pot, use a high nitrogen fertilizer every week for bigger greens. Look at the NPK rating and opt for organic fertilizers if possible.
You’ll be eating the watercress anyway, so why not? Use as directed.
Growing kangkong in a jar
This veggie can be planted indoors in a small mason jar or even a plastic bottle.
Get your container of choice. I prefer mason jars because they’re glass and it’s safer than plastic to avoid any leaching. They’re also easier to see through with no distortion. If you want to grow organic kangkong, use glass.
Put the cutting roots down into the water and use a rubber band or string to tie the stalk to the edge of the container. It should be held in place so it doesn’t sink.
The foliage will grow out of the container and the roots will grow below.
Using a jar is fun because you can watch the water develop and grow outwards while you harvest the leaves above the jar.
However, using a small container for veggies can lead to poor water quality quickly because of the small volume. Just keep an eye on it. Swap water when necessary. This is why using a glass jar proves to be beneficial.
Growing kangkong in water
Similar to growing from cuttings, you can grow kangkong completely in a pot of water! Choose a pot, basin, or other large pot of water to hold your kangkong.
There’s no maximum size, as this plant doesn’t need to be root bound to grow properly. The bigger the pot, the more you can grow. However, too big will make it awkward and unwieldy.
Keep it around 5 feet max in diameter for ease of use. A tiny pool can be bought for cheap and holes can be drilled through the plastic for a DIY plant basin.
The best type of kangkong for growing in water is Oak Quat, because it grows naturally in ponds and small bodies of water. Ching Quat can also be used.
The leaves and stems are light density and float on water. So they must be secured.
Next, you’ll need something to hold the kangkong. It needs to stay propped up so it doesn’t fall into the water on its side. The roots need to be held in one spot using a mesh wire or something.
The easy solution is to use some kind of soft mesh fencing fabric that can be draped over the container. Then each stalk can be secured in place using the small squares in the mesh wire.
Avoid using steel mesh because it’s hard to work with.
Or if you want to plant kangkong directly in the water, you can place the mesh so it goes into the water and hovers a few inches above the basin.
Use a very fine mesh so that it holds the seedlings in place, but doesn’t let them through. The plant will orient itself by growing roots down into the water and leaves above the waterline.
For the next few days, watch the roots develop under the mesh and get excited. They should appear within 2 weeks under optimal conditions. The leaves should grow above the mesh layer and the roots below it.
Pests
Kangkong is susceptible to pests that populate areas with high humidity, such as aphids and leaf beetles.
These can be controlled under careful monitoring and soapy water. Planting in the kitchen eliminates a lot of bugs.
Harvesting Kangkong
This plant is ready to go after about 2 months of growth.
You’ll notice that the leaves will be long and ovular.
When they’re over 4” in length, you can cut them to harvest.
Don’t cut all the leaves at once. If you want to harvest the entire plant, cut off the stem and leave about 2” behind. This will let the plant regrow to produce another yield.
Other common questions about planting, growing, and caring for water spinach
Here are some additional questions commonly asked by beginners growing water spinach at home. You may find these handy on your quest to grow this herbaceous veggie.
Is kangkong a perennial or annual?
Kangkong can be either depending on where you live.
If you’re in a colder climate, it’s treated as an annual veggie. But for those in warmer climates, you can grow and harvest it over and over so it’s a perennial.
Can you grow water spinach hydroponically?
Yes, water spinach can be grown hydroponically to save water. It basically grows itself. This plant benefits from the constant water drip irrigation because they like to be moist. But if you’re growing indoors, you’ll need a bright light to provide the necessary UV for it to flourish.
How long does it take to grow?
Kangkong will germinate quickly in just 2 weeks. After that, it’s just a matter of keeping it nourished until 2-3 months when it becomes edible and ready for harvest. The cuttings can be replanted and regrown.
How do you harvest the seeds?
The seeds can be harvested but it needs to flower first.
This means the water spinach must be planted outdoors in the sun for it to flower in the first place. After it flowers, you can harvest the seeds directly from the seed pods to replant.
Kangkong produces plenty of seeds so you should have enough to replant for a bountiful harvest. The seed pods are green stalks that grow off the main stalk.
Let them grow then harvest the seeds when the pods are beginning to split apart. Follow the steps laid out earlier to plant kangkong directly from seed.
Here’s a video that you may find useful:
Best uses
Both the leaves and stems are edible. You can use it in a variety of Asian dishes like:
- Oyster sauce
- Adobang kangkong
- Stir-fry kangkong
- Kangkong garlic
Additionally, kangkong makes a nice aquatic plant if you have an outdoor pond. But we all know that the main reason you’d plant it is to use it in a tasty dish!
Further reading
Here are some additional references you may find useful:
Now you know how to grow and care for kangkong
You now have all the basics you need to grow kangkong.
Water spinach is a nutritious, easy to grow plant that’s not common in the United States.
So you’ll be one of the few unique growers in the neighborhood!
You can plant, cut, and regrow this vegetable over and over so you never have to ship in the seeds again.
Do you have any questions? Post a comment and let me know! Will you be growing in a pot? Container? Or over water in a jar?
Kangkong is a versatile plant that can be grown in a variety of ways. Enjoy your harvest and eat up!
I’ve always been interested in gardening, but I never took it seriously until I was forcefully gifted an orchid. This was what got me into the hobby and I’ve never looked back. I enjoy writing about it, but not nearly as much as getting into the dirt and sculpting the perfect decorative ornamental to enjoy for the times.