Watercress (Nasturtium microphyllum)
Posted by Fiona Nevile in Vegetables | 37 comments
I always thought that you needed a stream of running water to grow your own watercress. I discovered that my friend Carol knows where wild watercress grows locally. Despite a bit of gentle pressure she refuses to divulge her secret. I’m not surprised, watercress is expensive. But if you follow Carol and discover her watercress beds, be on your metal. Dirty streams makes watercress unfit to eat. If you wouldn’t drink the water, you shouldn’t eat the watercress.
Unless you can use an entire supermarket pack within a day or so it goes floppy and has to be tossed out. Our compost bin has eaten far more watercress than we have over the past few years.
I used to envy Carol. Imagining her picking up her hat and basket. Breezing off to her secret place to pick just what she needed.
Now I grow my own.
Two years ago I discovered that Thompson and Morgan produce Watercress seeds. These are not available in many garden centres. I found them at Sctotsdales in Shelford but I discovered today that you can buy watercress seed on line direct from the Thompson and Morgan site.
Watercress seeds are quick to germinate. When they are strong plantlets, I pot them on. Five to a 12″ pot. These pots sit in old washing up bowls full of water in a shady spot. I change the water every other day or so, tossing the old water onto anything in the kitchen garden that needs a drink.
When harvesting, just trim the tops of the cress so that the stems will regenerate by producing side shoots. In this way the watercress will spread across the surface of the large pot. I think that I probably plant to many plantlets in each pot. I just want to guarantee a plentiful supply. Watercress can also be grown in the border in soggy trenches. I find the pot method works best for me as it is easier to see if they need to be topped up with water. If you are lucky your pots will give you a decent supply of fresh watercress from early summer until well into the autumn.
Watercress is packed with vitamins (A, C and K). It is a good source of iron and calcium and is full of beneficial glucosinates.
Always wash your watercress well. If you cultivate it in pots in your garden you probably are safe but watercress grown in running water can attract the liver fluke (Fasciola hepatica). This is rare. I saw it first on a returned plate in a London restaurant. We saw the fluke recently in a supermarket pack. The fluke is flat, with loads of legs and you can’t miss it as it is about an inch long.
I wonder if Carol would swap her local knowledge for a pot bursting with hand reared watercress. I’d still like to savour the wild cress as I’m sure that it tastes totally different to the cultivated cress and judging from Carol’s smile it’s absolutely delicious.
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I’ve grown watercress, my favourite salad crop, in containers for some years. I grow it from seed & prick out the seedlings into an old washing up bowl with holes with the bowl standing in an old trash bin lid filled with water. Here in Bermuda it is strictly a winter crop. I use ProMix & fertilize well. including iron. Initially I harvest by snipping the terminal shoots, but later it is preferable to gently pull out shoots, otherwise too much clipping causes production of too many small laterals. Eventually the substrate becomes too waterlogged & needs to be replaced or otherwise aerated.
I’ve read all the entries here with great interest. I’ve grown wtaercress this year for the first time from seeds from Chiltern Seeds. I grew it first in pots standing in water, then transferred it to the garden, into what should have been a boggy area of the garden but here in the extreme south east of the country we’ve had such a dry summer that it’s now quite dry! The watercress has thrived with almost no watering but I think the leaves are smaller than they would be in water, and the taste is quite strong. I’ve more or less stopped eating it now though as they’ve all been nibbled (by slugs presumably).
We’ve just put some in a newly-created pond to see how it fares there, but I’ll be very careful how I wash any we eat from that! I’ve seen occasional references to it being used as a pond-clearer – that having watercress in your pond can help inhibit algae growth – and I’d be interested to know if anyone has any views on that as further Google searches haven’t turned anything up.
Hello Mr Saunders
Thanks for your updates and superb information and links. Much appreciated!
Nice webpage. Interesting views, ideas, and information.
In the June 17th entry, I should have referred to “nitrate” contamination rather than “nitrogen”.
For wild watercress to be edible as pure salad, it should be growing close to a fresh spring, in a region where neither water snail nor various herbivore are producing millions of almost invisible liver fluke.
If wanting for some reason to eat watercress from a stream, then (as most streams contain water snail and have contact with herbivore of some kind) the watercress should (according to www patient co.uk; under:- “Fasciola Hepatica”) be soaked in 6% vinegar or potassium permanganate for 5-10 minutes. Alternatively, it can be made into soup, see:- (simonthescribe co.uk articles Watercresssoup), provided it’s taken to a sufficiently high temperature.
Hello Mr Saunders
This is a really helpful and instructional comment. Thank you so much for sharing your knowledge and experience.
So many people are keen to grow their own watercress so it’s great to know about any possible pitfalls. Thank you!
Watercress grown in a garden should be free of liver fluke, provided the garden is not watered with infected river water, and provided also that there are no pond snails in the garden.
If there are pond snails, and if river water has been used within the last year, then the pond snails could contaminate not just watercress, but also other food plants near the water.
In other words, it’s not just watercress that’s involved. In nature, any food plant can and does keep the liver fluke lifecycle going, largely involving sheep and cattle.
But a problem that’s connected more particularly with watercress, is that watercress from rivers can have a very high level of nitrogen contamination, as rivers carry nitrogen away from over-treated fields. A clue that watercress might contain too much nitrogen, is when it’s growing unusually vigorously.
Nothing is completely safe. Before eating watercress, try looking on Google Maps, or Google Earth, at the watercress beds where it was grown.
If a garden is free of the combination of pond snail and contaminated water then, regarding liver fluke, watercress grown there should be safer to eat than from other sources.
Hello Adrian
I grow my watercress in large pots standing in water that is changed everyday. I don’t feed them at all.
I gave my friend Carol some plants last spring and they are thriving in her stream with enormous leaves, four time the size of mine. This year I am going to give them tomato feed every now and then and watch what happens.
What nutrients does watrcress need in soil to grow well and plentiful.Regards Adrian
Hi Tamfish
I grow watercress every year and have great success with it. My friend Carol put some of my watercress in her stream and it has grown into a giant swathe of large leaves. She soaks it in salted cold water and rinses it before eating, just in case.
Umm, was thinking of growing watercress myself, not so sure about it now, what with all the nasties lurking in it!!.