When you think of watercress, does it evoke images of refined British ladies nibbling on delicate sandwiches? This leafy semi-aquatic vegetable, a traditional teatime staple, is making a comeback, and you don't have to be a stuffy, corseted blue blood to appreciate this easily-cultivated superfood.
Its Latin name ( Nasturtium officinale) and crisp, peppery flavor often lead to some confusion about its pedigree, but watercress isn't a nasturtium at all. It's a brassica, most closely related to mustard greens, radishes, and arugula. These are the sassier members of the brassicas, who are likely the ones stealing the keg at family reunions while cousins broccoli, kale, and cabbage are responsibly manning the grill or helping Auntie Cauliflower babysit the Brussels sprouts.
But still, we wince when we see nasturtium leaves and blooms in photos illustrating online articles about watercress.
Watercress is a low-growing, trailing herbaceous vegetable with bright green, rounded leaves and tiny white flowers. Watercress clusters can grow 18" to 24" tall, and while sources vary in classifying watercress, the National Gardening Association considers it to be a perennial, regrowing from rhizomes each spring.
Watercress' Rich Heritage
We love to name-drop when we share a plant's historical highlights, so we're happy to report watercress' connections to few historical celebrities.
Watercress has been valued for at least two thousand years as a nutritious food source. It's said that Persian king Xerxes demanded that his soldiers eat watercress to fuel their long marches, and his Greek nemesis Xenophon also encouraged consumption of the nutritious and refreshing green.
Another famous military figure, Napoleon, was known to personally enjoy watercress.
Hippocrates, the father of medicine, established his first hospital near a natural spring to cultivate wild watercress and take advantage of its purported value as a blood-cleansing remedy.
Romans reportedly treated insanity with vinegar and watercress, and the vegetable became a popular staple among Victorian working class and nobility alike when railroads made quick transport of fresh greens from the mineral-rich streams of southern England to British urban markets.
Limeys vs. Cressies
Mariners learned of watercress' scurvy-fighting properties thanks to herbalist John Gerard's 1636 findings, and Captain James Cook kept a supply on his travels to prevent scurvy among his crew and allow him to pursue his far-flung adventures.
In the 1930s, Britain's Ministry of Health conducted its own research on watercress and proclaimed its excellence for promoting healthy growth in children.
Precursor to the green bean casserole?
Here in the United States, watercress may have been on the menu at the first Thanksgiving. While our unrelenting team of researchers and highly-paid psychic mediums haven't been able to confirm this statement, we do know that watercress, which quickly naturalized in warmer North American regions and did come across with early settlers, was available to the pilgrims at that first harvest celebration...unlike popcorn, which only comes from corn varieties not then familiar to the First Nation locals.
Another Thanksgiving myth...busted! Sorry, kids!
Where Does Watercress Grow?
Watercress is thought to have originated in the Mediterranean and Asia, but it's quickly naturalized throughout western Europe and North America. Lewis and Clark recorded finding watercress while exploring the Lousiana Territory, a testament to how easily the plant naturalizes and spreads.
In the wild, watercress grows in clear, gravelly streams, but for home cultivation, it does well in damp, fertile soil or in water gardens and hydroponic systems containing ample nitrogen.
Watercress prefers a pH between 6.5 and 7.5, with some gardeners suggesting a more alkaline soil.
Though watercress does best in the higher USDA hardiness zones, it can grow in zone 3 climates as an annual, or indoors provided ample artificial light. This plant likes shade during the hottest part of the day but does need good sunlight to thrive, especially if grown indoors.
How to Grow Watercress
You might be tempted to transplant feral watercress from bogs, streams, and ponds, but beware of stowaway microbes and pest larvae that can spread to other water plants in your garden or cause illness when eaten. Once you establish your watercress from seed, you can transplant cuttings to expand or extend your harvest.
Once you've chosen your site, be sure it's properly amended with compost, fertilizer, and pH balancing minerals. While watercress loves moisture, it doesn't do well in stagnant water, so adding sand and aged compost helps keep plants moist and happy.
Watercress is at least 95% water, and its nutrient value depends on the quality of the soil and water in its immediate environment. Should you opt to experiment with hydroponics or gutter gardening, be sure to use liquid fertilizer to ensure you're getting a good return on your efforts.
Plant watercress seeds indoors six weeks before last frost 1/4" deep and 1/2" apart in small trays or clay pots set in a pan of water.
Direct seed outdoors after your area's predicted last frost, when daytime temperatures reach 65°F. Keep soil moist until germination, which usually occurs in 5-14 days.
Watercress transplants easily, so seedlings can move to their outdoor locations as long as they're not at risk of frost.
Watercress does very well as a container plant, though outdoor potted plants tend to dry out and heat up quickly. Keep potted, well-watered watercress in a shadier spot than those planted in the ground, or indoors in a sunny window.
Watercress is a fantastic plant for your first foray into aquaponics (water gardening using live fish as part of the nitrogen cycle) or hydroponics (plants grown in cycling, nutrient-supplemented water).
Your main challenge is keeping your watercress from drying out. Drip irrigation systems are ideal if you don't have a low-lying, constantly damp spot in your yard. Try growing watercress under a leaky hose spigot, or if your area experiences frequent rain showers, near a downspout.
Use care when applying manure fertilizers, as wet soil conditions encourage the growth of harmful microbes. Apply animal fertilizers at or below the soil surface, or (if liquefied or in tea form) from dishes underneath potted plants.
Pests and diseases
Watercress isn't particularly prone to pest infestation or disease, but slugs and snails love wet soil and any crunchy, low-growing leafy vegetable, so pick off or trap slimy critters as needed.
Keep an eye out for aphids and flea beetles, and treat accordingly.
Try interspersing watercress at the base of established tomato plants or near other vegetables that benefit from consistent watering. Watercress may act as a living mulch for the tomato plant, which in turn can provide midday shade.
Harvest and storage
Use the leaves or the hollow, juicy stems when they're still small and tender for cold soups, salads, or as a garnish. Watercress grows quickly so you can begin pilfering your plants as early as three weeks from germination.
It's best to harvest watercress greens before the plant flowers in late summer; otherwise, watercress takes on a bitter, unsavory flavor.
Watercress doesn't store well. It's best to use it as you pick it, so plant plenty to keep you in crispy greens throughout the season. It will stay crisp for a few days if you wrap it in a damp paper towel and store it in your refrigerator.
Watercress as a sprouting veggie
Watercress makes a healthy and nutritious vegetable sprout. Rinse and soak seeds for a couple hours before placing in your sprouting container. Place the container in a cupboard until seeds germinate, then out of direct sunlight, rinsing daily until sprouts reach desired size.
Exposing to sunlight the last day or two of the sprouting process increases the plant's phytonutrients, but don't let them overheat in their container.
Watercress for Your Health
We've already mentioned a few of the reasons why watercress was sought out as a life-sustaining and healing plant in the context of its historical origins and widespread proliferation. Now, it's time to take a closer look at Nasturtium officinale as a legitimate, proven source of wellness.
Our esteemed legal advisor (well, actually, my kid) wants you to know that we at Seed Needs don't endorse watercress as the end-all, be-all solution to any medical ailments, and we encourage our customers to check with their doctor before using any herbal concentrations for medicinal purposes.
Having said that, we are comfortable telling you that watercress is packed with vitamins A and C, B6 and B12, iron, folate, magnesium and phosphorous. It's even said that a serving of watercress contains more calcium than a serving of milk. Watercress is high in antioxidants and phytonutrients, which studies suggest help prevent certain cancers.
We came across an excellent article from Organic Facts that goes into detail (with citations and lists of academic studies) about how each of these vitamins and minerals—and phytonutrients specific to watercress and its close relatives—act to fight disease and promote good health. We encourage you to bookmark their page to learn more about watercress' role as a "superfood" but don't go just yet.
Watercress in the Kitchen
When cut fresh and kept cool, watercress makes a delicious, flavorful snack eaten "straight up", and we love watercress in tomato or cucumber sandwiches. If you something beyond what you can gobble down between chores in the garden, peel off your garden gloves and grab your pots and pans because we've found some great recipes for you to try!
Chilled Watercress and Almond Soup: Cold soups are making a comeback, and this one is a sublime recipe that highlights watercress' crisp and refreshing flavor.
Potage Cressonnière (Cream of Cress Soup): Beloved in France, and soon by your family. Trust us, you've got to make this at least once...or at least fly your clan to Europe and make someone else cook it for you.
Gingered Watercress is a delicious, easy-to-prepare Asian-fusion side dish.
Avocado and Watercress Salad: Ok, we were already sold, but you know that anything with a 3.5 out of 4 rating on Epicurious has gotta be good!
Watercress with Rice-Wine Oyster Sauce: Watercress is popular in Asia for good reason, so here's another stir-fry for our fancy-pants foodie readers. You know who you are; you own real chopsticks, and you know how to use them!
Watercress Tea Sandwiches: We're bringing things full circle with this classic watercress recipe. Break out the doilies, and practice sticking your pinkie finger out; it's time for high tea!
More Fun Facts about Watercress
Romans and Anglo-Saxons believed that watercress cured baldness. Romans fended off follicle follies by consuming the herbaceous plant, while one-upping Anglo-Saxons applied watercress directly to their scalps. (Come on, say it: "Cha-cha-cha-Chia Pet!")
The Latin root of nasturtium, which is the name Romans gave to watercress, is nasus tortus, which translates to "twisted nose". This doesn't mean watercress smells as bad as another bog plant, skunk cabbage, but that its peppery aroma makes one's nose twitch just a little when we sniff it.
Watercress may have been the first commercial "fast food." Victorian English street vendors would sell bunches of watercress to passersby, to be eaten straight from the fist, " like an ice cream cone". Boy, have times changed.
When you buy your watercress seeds from Seed Needs, you're not only purchasing fresh, viable seeds hand-packaged at our family business; you're helping us provide food, education, and medicine to 25 kids in poverty-stricken countries through Childfund.org and Compassion International. We're proud to help our customers grow nutritious food in their own backyards, and thanks to your patronage, we can pay it forward!