A thin layer of peat is spread out on the floor of the propagation unit. Watercress seed is spread over the peat, watered, and after about 10 days (depending on temperature) is ready to be planted. It is shovelled from the floor and loaded into planting bins
The method of planting seedlings is one that has been used for many years. Bins of seedlings are put at regular intervals down the bed wall, and the planting staff then fill buckets from these bins and spread the seedlings evenly over the surface of the bed.
Once the seedlings have established themselves and rooted into the gravel bed, the water flow is increased to provide them with the nutrients they require. At certain times, these nutrients need to be topped up by fertiliser applications. Overhead irrigation is used to help keep insect levels down
When the crop is ready for harvest, an experienced team go in to the bed with harvester and cut the watercress into harvest crates. Each crate holds around 6kg. These harvesting crews can harvest up to 3 tonnes of watercress an hour. Each harvester is equipped with a shaker belt, which shakes the watercress to remove any insects or other contaminants that might be present.
Once harvested, need to be cleaned out ready for the next crop to be planted. The material removed from the beds contains a fair amount of gravel. This is left to rot down, and then the remaining gravel is washed, graded and reused.
After being cleaned out the beds are then levelled. First they are raked and then a team will fill in any low spots with additional gravel and rake out any high spots. This allows the water to flow evenly over the bed surface once the seedlings are planted.