Welcome to our How to Grow Chinese Vegetables series. It’s the last post of the 2023 growing season, and we’re talking about how to grow watercress, or xīyáng cài (Mandarin)/sai yeung choy (Cantonese) – 西洋菜.
My dad used to pick wild watercress with his family in the streams and brooks near where he grew up (in the Catskills of New York). Since then, he has always wanted to grow his own. We’re happy to report we now have a few nice patches of watercress growing in the stream that runs through our yard!
However, you can grow it in containers as long as the soil is kept consistently moist. Watercress is also a perennial, so if established in a more permanent growing position, it’ll come back year after year.
Why Grow watercress?
Watercress (nasturtium officinale) is an aquatic plant in the cabbage family that grows naturally along slow-moving waterways. It has a peppery flavor when raw that mellows after cooking.
While in Western cuisine, it is often consumed raw and in small amounts (either as an herb, in salads or sandwiches, or as a garnish), it is enjoyed in Chinese cuisine in larger quantities, usually stir-fried and in soups.
Watercress is packed with fiber, vitamins, and minerals. When you eat it cooked rather than raw, you actually end up eating more of it, so that your body can take advantage of all those benefits!
Recipes Using Watercress
We have several key Chinese recipes that use watercress:
This is the most common way we enjoy watercress in our family. We wash it really well, and simply stir-fry it with ginger, garlic and salt. It also tastes great when stir-fried with fermented tofu! When my mom is at the table, we always have to have a leafy green to go with dinner. Watercress is a go-to!
This watercress soup with pork bones or pork ribs is another family favorite. It’s incredibly simple to make, with just 6 ingredients. You’ll be surprised at the depth of flavor that the watercress gives to the broth! Serve this soup with a dish of light soy sauce for dipping the pork into.
This is a classic dim sum recipe. Ground beef is whipped with watercress to make a flavorful steamed meatball that you can enjoy with other dim sum delights!
Okay, now that you know how versatile it can be, let’s talk about how to grow watercress!
How to Grow Watercress
While we grow many of our vegetables from seed, starting a patch of watercress is as easy as rooting some stem cuttings from store-bought watercress. (The best part is, once you’ve processed the stem cuttings, you can then eat the tender leaves!)
We have found that growing watercress from seed is a bit difficult, as younger plants can be hard to establish (especially if there’s a heavy rain, in which case they might get washed away).
We simply bought a few bunches of watercress to cook and enjoy, but before we washed it for cooking, we chose some choice stems with nice nodes on them, removed most of the top growth, and rooted them in a glass of water:
Keep the cuttings in bright indirect light, and they’ll begin to form roots within a few days. Change out the water every few days. Do this in springtime, a couple weeks before the last frost date in your area.
Once your watercress cuttings have formed strong roots and any danger of frost has passed, you can plant them out.
Watercress grows best in shallow, slow-moving water. If planting them in a stream bed, plant them along the edges of the stream or creek, between rocks so that the roots have something to hold onto.
We had a few heavy rains in spring, and some of our planted cuttings did get washed away when the stream filled up.
My aunt (my dad’s sister) was most successful in putting our rooted cuttings in the ground. She mostly planted them along the stream’s edge in and amongst rocks, or in one case—in an old tree stump! We did this back in early May.
Over the course of the summer, we let the plants establish, and we’re now able to harvest some nice bunches!
If you don’t have an area of moving water to plant watercress, you can also grow it in containers, as long as you keep the soil consistently wet. Place the container in a tray filled with a couple inches of water to keep the roots nice and moist, and don’t let it dry out.
Watercress needs clean, clear water to thrive and doesn’t do well in stagnant water. Refill/change the water once a week or as needed to keep it fresh. Rainwater is best —just put out a bucket or other container to collect it.
We have even seen people cultivate watercress in containers that are actually floating (moving) in another larger container of water to mimic the movement of the water in its natural growing environment.
Ideal Growing Conditions for Watercress
Watercress prefers relatively mild/cool weather, and tastes best when grown in such a climate.
The plants prefer full sun. Like many other leafy greens, sunny yet cool conditions are ideal! In hotter climates, partial shade is best.
We actually grow it in a lightly wooded area that gets full sun in spring before the trees have leafed out and dappled shade in the summer. This seems to be ideal, as the watercress has some protection from the high heat of summer.
Watercress will grow in various types of soil (including clay soils, sandy soils, chalk, loam, or silt), but whatever the growing medium is, it does have to be kept moist. Watercress also prefers a pH of 6.5 to 7.5.
You can harvest watercress at any time throughout the year. It is a cut and come again perennial, which means as long as you keep harvesting, it will keep growing!
Periodic harvests will also slow down flowering and seed production, which is good…because once the plant flowers, its flavor will be compromised.
Continue to harvest leaves and young stems regularly. The vegetable tastes best when harvested in cooler seasons—spring and fall.
Watercress is prone to some pests—particularly moisture-loving slugs and snails, as well as white flies.
1. Slugs & Snails
Slugs and snails are moisture-loving creatures, so of course they love watercress! There isn’t too much you can do about them, besides removing them from the leaves as you see them. When washing store-bought watercress, we even find snails in the leaves sometimes, and the damage is usually minimal.
If you have a case of whitefly, you can spray the leaves with a jet of water to remove them, or also use an organic pest control spray like neem oil.
We hope you enjoyed this post on how to grow watercress. Now that it’s the end of November, it’s time to start thinking about next year’s garden!
We hope that our how to grow Chinese vegetables series has inspired you with some new ideas for next spring! Here’s a full list of what we’ve covered so far: