How to Grow Watercress Indoors

by Sandy Swegel

Watercress is another one of those unassuming, almost weedy, plants that is a superfood for humans. In the brassica family of heirloom vegetables, watercress (Nasturtium officianale) is rich in vitamins, minerals (especially calcium) and sulfides. It’s not just for watercress sandwiches and tea. It is a great addition to salads as either sprouts or leaves, excellent juiced or added to juices and makes a lovely pureed spring soup. And pretty yummy just for nibbling.

Watercress is a great plant to start at the beginning of the growing season, but you can also grow watercress indoors during winter. We’ll teach you how.

 

Sprouts

Watercress sprouts easily and you can grow it in a jar just like you do alfalfa seeds. Its spicy kick is great on sandwiches and salads.

Plants

Seeds are pretty easy to germinate. The biggest challenge to grow watercress indoors is that it needs to always be moist, especially during germination. You can accomplish this by starting the seeds in a small pot of clean potting mix and then setting the pot in a saucer of water. Misting is great or put a plastic cover over the seed mix if your air is dry. Someplace slightly warm like the top of the frig is a great germination spot. They don’t need light to germinate.

 

Once the seeds are growing, you just need to be sure the plants are moist with fresh water. Think about their ideal natural habitat in Europe: slow-moving creek edges in bright shade. Some people grow them in water tanks with aerators if you want to get fancy.

One secret to tasty watercress is to keep the growing plant cool and out of hot sun and to harvest it before it flowers. After flowering, the leaves become more bitter.

 

To grow watercress indoors in late winter is such a promise of Spring. But it doesn’t need to be an indoor plant. After your weather warms to above freezing, you can plant your watercress outside if you have a place that stays pretty moist. (Learn more about Zones and Frost Dates). If you have a pond or fountain the watercress is thrilled living in a pot in about an inch or two of water along the edge. I’ve seen it in a shade pot with impatiens and it was pretty happy.

And once you have nice succulent leaves, watercress, slivers of cold cucumber and butter on thin white bread is actually pretty awesome.

 

Not sure what heirloom vegetables are or why you should grow them? Read more from Gardening Know How.