Towpath botany

Brewing, toy-making and warding off evil spirits: senior ecologist Paul Wilkinson investigates how towpath plants have been used by boat-dwellers for the past two centuries

Illustration: Alan Baker


In many ways, our towpaths – built for the horses that pulled narrowboats along the canals – have changed little in the past 250 years, while the surrounding landscape must seem unrecognisable. Over the years these towpaths, and the waterways flowing beside them, have allowed seeds to disperse and plants to take root. And, despite hundreds of years of being trampled by horses, people and dogs, a dynamic mix of species have held on. Many of these plants provide a real insight into the lives of the people who lived and worked on our waterways. Let’s take a closer look…

Soapwort, Saponera officinalis

“It’s likely people who lived and worked on the canals used this plant instead of soap,” says Paul. The leaves and roots of the Saponera officinalis – a dainty pink flower that blooms along the towpath from June to September – are rich in saponin, which produces a lather in water. The Romans cultivated Soapwort close to their bathhouses and even today conservators harness its gentle cleaning properties for lifting dirt and grease from ancient textiles. For a quick hand wash while you’re out on a walk, simply crush the leaves and rub into your hands.

Mugwort, Artemisia vulgaris

This silvery mat of narrow, spear-shaped leaves is known as ‘sailor’s tobacco’, as the dried leaves were smoked as an alternative when sailors ran out of tobacco at sea. “This bitter-tasting plant was used to flavour beer before hops,” says Paul. It was blended with other botanicals to make ‘gruit’ – a herb mixture used for bittering and preserving beer before the general use of hops in the 15th and 16th centuries. Like St John’s Wort, it was also used to ward off evils spirits as part of St John’s Eve festivities during the summer solstice.

Blue fleabane, Erigeron acris

Blue fleabane is a member of the daisy family, recognisable for its lilac-coloured petals, yellow centre and hairy, spear-shaped leaves. “This plant is typically coastal but was able to colonise inner cities via the canals,” says Paul. Along the canal, you’ll find it growing on walls and in dry, grassy places. The name ‘fleabane’ derives from its historic use as incense to drive away insects. It’s also rumoured to relieve toothache and arthritic pain.

St John’s Wort, Hypericum perforatum

“This valuable plant has been used to treat depression for centuries,” says Paul. This golden-flowered herb has a long history as a herbal remedy. It’s also strongly linked with pagan and Christian midsummer festivals, when it was used to ward off illness, bad luck and evil spirits. The name is believed to derive from the blooming of its flowers in time for St John’s Day (24 June). The dark spots on the flowers are said to represent his blood, and the translucent spots on the leaves represent tears shed over his death.

Toadflax, Linaria vulgaris

“This precious bee plant often indicates a past industrial landscape,” says Paul. The handsome wild flowers are easily mistaken for snapdragons, but can be distinguished by the long spur behind the flower head. This spur is a bumblebee magnet – the bee muscles its way in and uses its long tongue to get at the nectar inside. ‘Linaria’ derives from the Latin linum, which means flax or linen, but this is due to its similarity to a flax plant, which was historically used to make linen. Its nickname ‘butter and eggs’ refers to its pale yellow and orange flowers.

Silver birch, Betula pendula

We all know this beautiful and elegant tree for its white bark and pale green leaves, which turn yellow this time of year – but did you know that the silver birch has been put to good use by canal folk for centuries? “The bark of silver birch would have been used to make string and rope,” says Paul. “The wood fuel would have been used for fire and the sap brewed into alcohol.” Its distinctive bark has long been used for tanning leather, and the tough, heavy wood is ideal for making furniture and toys. For decades the wood was used to make bobbins, spools and reels for Lancashire’s prolific cotton industry. Its nutritious sap even makes a refreshing drink!

Stinging nettle, Urtica dioica

It may be the bane of bare legs in summer, but the humble stinging nettle has an abundance of amazing and surprising uses. “Nettles would have been a valuable food source as they’re reputedly more nutritious than spinach,” says Paul. “The stripped stems would also have been used to make rope.” The leaves of a nettle, which have a spinach-like flavour, are rich in iron and vitamins A – ideal for steeping in tea or whizzing into a soup. When picking nettles, only forage young leaves near the top of the plant from late February to early June (older leaves have an unpleasant taste and texture) and be sure to wear gloves!

Horseradish, Armoracia rusticana

What would a slab of roast beef be without a dollop of horseradish sauce? “Horseradish, very common now along the edges of the towpath, was introduced to Britain from eastern Europe for the value of its hot, spicy flavour,” says Paul. No one is certain where its name derives, but one theory is it’s a mistranslation of the German name for it, meerrettich, which means sea radish. It’s believed the English mispronounced it ‘mare radish’, which later became ‘horseradish’. In autumn, the root is ripe for picking. The long, glossy green leaves of horseradish are easily mistaken for dock – if you’re unsure scrunch up a leaf and have a sniff, it should smell of horseradish.

Be careful when investigating plants. Always make sure you take a reliable guide book or an expert with you when foraging.