The peppery leaves of watercress can be expensive to buy at the supermarket, but you can easily grow your own fresh leaves at home at a fraction of the cost. Contrary to what you might have heard, you don't need a stream running through your garden to grow watercress. You don't even need a garden - a large pot and a shady spot is all you'll need for regular harvests of these vitamin-rich leaves throughout the summer.
Growing watercress in containers is a safer option than growing it in water - commercial growers know how to keep the water fresh and bacteria-free, but this is much harder to do in a garden situation.
As long as your watercress plants are kept well watered they’ll thrive in a pot of good quality compost. To provide the right growing conditions for watercress, simply stand your pots in deep trays or dishes that are kept topped up with water. To prevent any stagnation, make sure to flush the pots heavily twice a week with fresh water. Mixing charcoal with the compost will also help to keep things fresh.
Don't go chasing around looking for watercress plug plants - growing watercress from seed requires no special skills or equipment. Simply sow the seed directly into containers during March and April, or as soon as the average daily temperatures reach 8-15°C. Germination should occur within 14 days.
There’s no need to cover your seeds. Just sprinkle them over the surface of moist compost and they will sprout happily. Sow regularly through spring and early summer for a constant supply of fresh leaves.
If you want to grow watercress seed as a microgreen on your windowsill, simply sprinkle seeds over the surface of pre-saturated soil in small seed trays. Once growth is underway, keep the trays on saucers of water and harvest your watercress microgreens with sharp scissors when the plants are about 5cm (2") high.
Top tip: If you have a surplus of fresh leaves through summer, don't let them go to waste. Rabbits and guinea pigs eat watercress and will enjoy this tasty treat whenever you have some to spare. Pet birds may also appreciate the fresh leaves too.