We stopped at Stoke Lock and cooked up a feast in the evening for fifteen guests. Despite my concerns that we wouldn’t have enough food, the experimental cooks aboard the floating kitchen conjured up enough to feed everyone. We sampled nettle and hazlenut tart with hawthorn chutney, wild cabbage stew, foraged salad, apple crumble, and lots of gorse flower wine that I’d made in the spring.

In the morning we returned slowly back up the river. Annwen Jones guided us in some medicine-making from the plants we’d foraged: We made comfrey ointment for joints and sprains, and elderberry syrup to ward off the flu.

The river is a different world. A slower paced, thoughtful, connected space. The river embodies the contradictions of the meeting of cities and nature: water that glitters despite its grime, pockets of wildness and abundance between industrial sites, an apple tree flourishing near to the dual carriageway that bridges the Trent.  It’s an edge, a hinterland – and traversing the river reveals the behinds of places, the bits you don’t normally see. The river is also a corridor: travelling by narrow boat is slow-motion escape as we slide out of the city. Making time to be here changes time, twenty-four hours becomes a week, we are out of the ordinary.

Fergus took us to several different locations, to sample plants that require different habitats. Near to a river, we picked the young shoots of Giant Hogweed, which contain a sap that causes skin irritation. However, carefully cut and steamed til tender, Hogweed shoots are delicious and tender like asparagus.

We tasted the stems of Burdock, Common Dock and Bristley Oxtongue – all stripped with a knife to reveal fresh crunchy stems with distinctive textures and flavours. In the woods, Fergus showed us a silver birch tree he’d tapped earlier in the year, and we tasted the Birch Sap syrup he’d produced – an incredible foraged sugar. (Although it takes a huge amount of reducing down, so each litre of syrup requires approx 80 litres of birch sap). We tasted a plant in the cruciferae family called Dittander. I nibbled a leaf and was shocked at overwhelming powerful flavour of mustard, as strong as a hot chilli, that made my eyes water.

For lunch, we ate  foraged feast: a salad containing 18 different ingredients, Quiche made with acorn flour pastry, sea kale and parasol mushrooms, and mashed potato with Dittander. Fergus had prepared two deserts: a milky pudding made with a seaweed similar to Irish Moss or Carraghean, to set it into a jelly-like consistency. And Sea Buckthorn juice sorbet – which had an amazingly zingy acidic flavour.

In the afternoon we visited a lakeside, and tasted the inside of the base of a reedmace stem.

The final part of the day was spent exploring the coast. We tasted many more plants – from the aniseed-like Alexanders, introduced by the Romans, to the cooked stems of Japanese Knotweed, that are remarkably similar to rhubarb. We had a dramatic dinner on the beach: Fergus cooked six different types of seaweed, throwing them one by one into a pan of hot oil over the fire, like a magician performing a ritual.