The foraging swimmer

Fancy turning your next swim into a foraging adventure? Ethnobotanist Susanne Masters on what to look for - and how to carry it

Transporting edible aquatic plants in a towfloat. Photo: Susanne Masters

Tethered to river banks, lake edges, and sea shores there are a host of plants that grow next to, on, or in water – many of which are delicious in drinks. Being dressed for swimming doesn’t preclude collecting a dash of edible plants to use when back on land. A tow float or thinking creatively will find a way to bring  your flavours back to the kitchen. 

Sometimes it’s a handful of water mint and meadowsweet I tuck between two swimming hats while on a river swim, to make a fragrant warming up tea afterwards. I often nibble an aromatic leaf of rock samphire walking back up from rocky seashore swims, thinking that I must try one of the gins that use it. Sugar kelp is an ingredient I selected while researching ingredients for the Isle of Harris Distillery. At a riverside party I shared a post-swim watercress gin made by Winchester Distillery. Aquatic plants aren’t just a sight to enjoy while swimming – they are also something to savour on land in a glass or mug. Here are a few of my favourites.

Water mint  – Mentha aquatica

Often detected as you stand at the edge of the water and inadvertently crush its leaves, this is the mintiest mint that grows wild about the water. You are unlikely to confuse it with pennyroyal (Mentha pulegium) a rare plant in the UK, best looked at and not consumed not only due to its rarity but also because it is hepatoxic. Enjoy watermint (Mentha aquatica) or cornmint (Mentha arvensis) as a fresh hot tea or make a mint julep whisky cocktail with these more fragrant cousins of spearmint. Alternatively, let James the resident forager for The Botanist who picks watermint for The Botanist gin do the work for you. 

Kelps  – Laminaria species

I selected sugar kelp  (Laminaria saccharina) for Isle of Harris gin because it combined the social and economic history of the island with a soft maritime flavour. Yes – sugar kelp really does taste a little sweet. Sugar kelp and oarweed (Laminaria digitata) can both be used to make your own dashi, a foundation of miso or just a savoury hot drink. Indeed Japanese dashi does not use our native seaweeds, but our kelps also brim with that umami flavour.  Or take a sweeter route and make seaweed cordial by following this recipe from The Botanist. 

Growing in relatively shallow water it is only a duck dive down to cut a frond off kelps, leaving their holdfasts to regrow. A band of sugar kelp is easily held in hand while swimming. Bulky oarweed is awkward to hold while swimming, but easily transported by wrapping a frond around a swimsuit strap so that the rest of its fronds trails behind you like a cloak. 

Susanne with freshly collected kelp. Photo: Philip B. Stark

“A band of sugar kelp is easily held in hand while swimming. Bulky oarweed is more easily transported by wrapping a frond around a swimsuit strap so that the rest of its fronds trails behind you like a cloak.” 

Rock Samphire – Crithmum maritimum

Always growing near the seashore, rock samphire is an incredibly concentrated burst of flavour. In the UK, it used to be collected for pickling but the habit was lost in time. Now you can taste it bottled in several gins  – such as Wight Mermaid, Curio Wild Coast, and Fishers. Or pickle in brine it to drawn out its flavour in liquid form. Then use your rock samphired brine in a pickleback to chase a shot of whisky.

Marsh Samphire – Salicornia species

Absolutely not closely related by genetics or taste to rock samphire, this is another waterside plant that has made it into gins – Gin Mare and Conker among them. You will often find marsh samphire around estuaries or muddy shores. It’s definitely a plant that needs scissors to collect as pulling the plant uproots it – which is illegal unless you have the landowner’s permission – or sends you falling onto the floor as it remains rooted. It is plump and juicy, which is how it thrives despite being a land plant growing with roots in salty water. A couple of sprigs are a perfect edible garnish for a martini.

Rock Samphire
Marsh Samphire
Water mint

Watercress – Nasturtium officinale

Be careful when you pick watercress. It tends to grow mingling with other lush waterside plants. Mistaking hemlock water dropwort (Oenanthe crocata) for watercress is a fatal error. Watercress is also a host for liver fluke parasites. These are killed by heat, so if you eat foraged watercress perhaps stick to using it in soup or dishes where it is cooked.  Commercially-grown watercress kept away from sheep – the other hosts for liver flukes – is fine raw. If you are a juicing fanatic, add it into juice for a bright green colour and sharp flavour. Twisted Nose is the gin to try if you are looking for an easy way to taste watercress: it is a key flavour and is made by a distillery at the edge of a chalk stream-fed watercress bed. 

Meadowsweet – Filipendula ulmaria

Growing in damp patches of meadows and often in abundance along riverbanks, creamy flower heads of meadowsweet offer a bewitching sweet almond aroma. If you dry these delicate petals for use later in the year, ensure that they dry fast and thoroughly – in a dehydrator or on dry sunny days – as when dried slowly in damp conditions they are prone to having toxic mould grow on them. Meadowsweet flowers can be used fresh or dried in cold cocktails and cordials, blending well with citrus peel and berries. Or use them to make a fragrant hot tea, perhaps with a splash of rum added as it cools to drink it pirate-style. 


My favourite foraging book remains ‘Wild Food: A complete Guide’ by Roger Philips. My dad paid for it when I was rummaging in a book sale 30 years ago – little did he know edible wild plants would turn into a job for me. If you would like a little more guidance on getting to know plants you can check the Association of Foragers directory for people leading foraging courses near you. 

Susanne Masters