Watercress is commonly known as the ‘power food’. With more than 15 essential vitamins and minerals, its health-giving properties have been known since ancient times. Indeed, unlike almost every other fruit or vegetable that is farmed, there is unaltered by breeding or selection and today is identical to the plant eaten in Greek and Roman times.
Gram for gram, watercress contains more vitamin C than oranges, more calcium than milk and more iron than spinach. But people love it for its flavour. Its peppery heat comes from the plant’s mustard oils, which are released when chewed and act as a stimulant to digestion.
Watercress has long been an integral part of the British diet, probably because it grew wild in rivers and streams and therefore could be picked for free.
Watercress grows all year round as it is protected by high and low temperatures due to the flowing spring water that leaves the ground at a constant 10-11 degrees.
Watercress seed can be directly sown into the Watercress beds or planted in protective tunnels and grown in 3cm -5cm in dense mats of seedlings with densities of 20-30,000 stems per square metre.
The seedlings are then planted out to cropping beds as a ratio of 2-3000 stems per square metre.
The plants quickly root into the gravel and as they take hold and grow, the rate of water flow across the beds is gradually increased. The greater the water flow, the greater the nutrients brought to the plants.
The crop is ready to harvest after 4 weeks in summer and 4 months in winter.
The crop is cut in an orientated manner, ‘head-up’, generally by hand with a knife and laid into crates. These are then chilled to less than 5 degrees and bunched.
If the Watercress is to be used for prepared salad, the crop is cut ‘un-bunched’, put into crates and chilled to less than 5 degrees, and then washed by submerging in tanks of flowing water.
Each summer, some of the Watercress is allowed to flower and set seed, and then this seed is dried and stored for the next planting round.
It was only in the last 150 years or so that Watercress was properly farmed. Early Ordinance Survey maps show a farm being listed on this site around the 1820’s and Watercress farming began here around in the 1840’s.
Watercress requires fresh pure mineral-rich spring water to grow, and the natural springs at Cassiobury Farm & Fishery bring water which exceeds modern day mineral water quality tests.
In its Victorian heyday, the majority of Watercress farms were built either in Hampshire, Dorset or Hertfordshire where the right water flow could be found. The development of the railway enabled tons of Watercress to be transported each day to London’s Covent Market where it was eaten in the hand, rather like an ice cream cone.
A small railway was built at this Farm to take the Watercress from the processing plant down to the canal, and from there into London. You can still see the remains of the old railway line in Watermint Meadow.
The Watercress industry continued through both World Wars, and you can see the bomb shelter at the other end of the Farm which was used to protect farm workers during raids. By the 1940’s over 1,000 acres of Watercress were under cultivation; but then the decline of the railway, a drop in demand, and overseas competition meant that by 2000 only 150 acres was being farmed. This site was believed to be the 4th largest Watercress farm in the UK when at full production; able to deliver 2 million bags of watercress a year.
Despite it’s noble history, Watercress became thought of as just a garnish, but in 2003 the British Watercress growers took action and launched a new campaign called ‘Not Just A Bit on the Side’ and the industry is now enjoying a renaissance.