Photo - Linda Ross
For a peppery zing in a salad or sandwich, and a serious green heat in a silky soup, you can’t beat watercress. Fortunately it’s as simple to grow, as it is good to eat.
My local creek is about as miserable as a natural waterway can get. The water barely trickles, the creek bed is full of silt, livestock destroy the banks, and it’s choked with privet, which the local council (in its wisdom) routinely sprays with herbicide that washes downstream and into one of Toowoomba’s main drinking water storages.
Where the creek does deserve the name, watercress has set up camp and grows in great profusion. I’d love to be able to tap this resource as an everyday, all-you-can-eat, wild salad bar. But alas, cattle grazing upstream means potential liver fluke in the watercress downstream and I’m reluctant to ruin one of my more vital organs.
The good news is that you don’t need a mountain stream, or even a pond to make this brassica happy. Watercress will grow happily in reasonably fertile garden soil on two conditions: it must drain well; but never completely dry out. So, in sandy soils add compost; and in clay soils, add compost. Organic matter creates the ideal combo of drainage and moisture-holding ability.
Like other brassicas, watercress is easy to start from seed. The ideal time to sow is in February, giving the plant a chance to produce lush leaves as the weather starts to cool in autumn and early winter. Direct sowing into the garden is possible, but I like to start the plants in punnets and transplant after about a month. To extend your harvest, make a second sowing in April for eventual use in late-winter salads.
Assuming you’ve kept your watercress plants well watered, they will produce plenty of leaves that can be picked as required. The easiest technique is to grab a bunch, and cut the stalks with a knife. Give the leaves a wash, and keep them fresh until use by storing in a plastic bag in the fridge. They’ll stay crisp for a few days.
Being a brassica, watercress can be prone to cabbage white butterfly attack. I’ve found that it’s easiest to throw a fine weave net over the plants. This offers extra shade and wind protection in addition to excluding the butterflies.
Don’t grow watercress in stagnant water - it will cause root rot. Watercress likes things clean and fresh, hence the reason drainage, and moisture-holding capacity, are important.