Growing nutrient-dense and delicious watercress at home is easier than you might think.
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Watercress(Nasturtium officinale)is famous for its peppery taste and rapid growth.
It’s a cut-and-come-again plant providing repeated servings of greens for salads, sandwiches, and soups.
Credit:Ali Majdfar / Getty Images
Perhaps the easiest way to grow watercress at home is not in the ground but in pots.
You need only a few pots, clean water, a nutrient solution, and light.
Note:Watercress is toxic to dogs, cats, and horses.
It also grows along pond edges and ditches in gravelly soil.
If you grow watercress outdoors, be careful not to introduce it to nearby ponds or waterways.
The U.S. Forest Service lists watercress as invasive and noxious in 46 states.
A smallgrowing station with supplemental lightingon a timer provides all the light watercress needs.
Rockwool makes starting seeds easier, and the entire plug can be potted up or planted in a bed.
Then, wipe the seed off the toothpick and onto the seed-starting medium.
Start seeds anytime for indoor growing or three to four weeks beforeyour last spring frostfor transplanting outdoors later.
Simulate its natural environment, and it will grow rapidly and well.
Light
Watercress does best and grows fastest infull sunbut will also grow well in partial sun.
Avoid areas of heavy shade.
This is a cool-season plant, so choose a location withmorning sun and afternoon shadein the heat of summer.
Watercress tolerates arange of pH levelsbut prefers water and soil that are slightly alkaline.
Watercress grows in and around water in nature and needs to be kept in wet conditions.
Keep the soil or medium damp, if not wet.
For microgreens, water from the bottom and don’t allow the medium to dry.
Temperature and Humidity
High humidity is best.
If your location experiences excessively dry air, you may need to cultivate watercress indoors.
When growing watercress as a microgreen, keep the temperature at about 65F to 75F.
Outdoors, mature watercress does fine in temperatures above freezing.
Fertilizer
Watercress grown outdoors to maturity in rich, organic soil does not require fertilizer.
Fertilize watercress grown indoors with a hydroponic nutrient solution, following the instructions on the label.
Pests and Problems
Watercress doesn’t suffer from many disease issues.
Common pests like snails, rabbits, and munching caterpillars can be problems outdoors.
Scatter the seeds and lightly cover them.
The seeds are tiny, so don’t bury them more than a 14 inch deep.
Keep the starting mix moist (but not drowning).
Division:Watercress can be easily divided and replanted.
To do so, tease the stems apart and separate a section of roots and vegetation.
Transfer the division to a new pot or location and provide water.
Cutting:Take a cutting from an actively growing plant.
A 6-inch cutting works well.
Use clean, chlorine-free water.
The stem will start to root in about a week.
Harvesting Tips for Watercress
Watercress flavor is best when you harvest it before the plant blooms.
For mature plants, cut back the stems, leaving about 4 inches remaining to begin new growth.
Both the stems and leaves are edible, but thicker stems can be tough.
Harvest watercress frequently to keep the new growth tender.
Frequently Asked Questions
Absolutely.
Just about any container will do, as long as holes allow water movement.
Unlike most plants we grow in containers, watercress likes its feet wet.
The pot-within-a-tub method is an easy way to provide your watercress plants with all the moisture they need.
Watercress can grow in a jar with a gravelly substrate like hydroponic rocks.
Change the water every three to four days.
Nasturtium (Watercress).
ASPCA
Watercress (Nasturtium officinale).
