Hogweed

Safety warning

Hogweed sap burns skin in sunlight. Common hogweed, Heracleum sphondylium, carries furocoumarins, including bergapten, in its sap, stems, leaves and fruits. Sap on skin makes it react to sunlight, with redness, blisters and burns that can last for weeks or months. Wear gloves and long sleeves when you gather and chop it, and keep sap off your skin and out of your eyes.

If sap touches your skin, wash it at once with soap and water and keep the skin out of sunlight for 1–2 days. If sap gets in your eyes, rinse them with water for at least 15 minutes. Seek medical advice if symptoms persist or get worse. Wash any clothes and tools the sap touches.

Never confuse it with giant hogweed, Heracleum mantegazzianum, or with poison hemlock and other toxic plants of the carrot family. Giant hogweed has thick, bristly stems blotched with purple and can reach 5 m; its sap causes severe burns and scarring. Poison hemlock is deadly in every part, and people mistake it for cow parsnip, wild chervil and wild carrot. Never gather from a plant with purple-blotched or purple-spotted stems.

Gather hogweed only when an expert botanist or experienced forager has confirmed the plant in person. If you have any doubt, do not forage it at all.

The European Food Safety Authority lists common hogweed among botanicals with substances of possible concern for human health in food, because of its furocoumarins. No source gives a safe intake, and none assesses hogweed in pregnancy. If you are pregnant, breastfeeding or have a medical condition, ask a doctor before eating it.

A meadow plant of the carrot family

Hogweed, Heracleum sphondylium, is a perennial of the carrot family, Apiaceae. It grows on fertile meadows, on roadsides and around farmyards, and the genus ranges across Europe, Asia and North America. The Royal Horticultural Society gives common hogweed a height of up to 2 m, with leaves more rounded than those of giant hogweed and stems without purple blotching. Gloger describes it growing tall on meadows and near villages and flowering in June.

Like other members of the family, it has alternate leaves whose bases widen into a sheath around the stem, furrowed stems and small flowers gathered in compound umbels. The parts used as food were the young leaves and stalks, gathered in spring before the plant flowered.

Names

In Polish the plant is barszcz zwyczajny, and barszcz was its name long before it named a soup. Brückner gives barszcz as the old Slavic name for Heracleum, with related plant names in Czech and Slovene, and links it to the sharp, bristly leaves. In Rabka Zdrój a 1948 survey recorded the local names borszczek and burak dziki, wild beet. Fedorowski recorded borszcz east of the Białowieża forest. In English the related North American species is called cow parsnip.

Hogweed in fermentation

Hogweed is the original ingredient of Polish barszcz. Young leaves and stalks, sometimes with flower heads, were chopped, covered with warm water and left for a few days until sour, then cooked into soup. Marcin of Urzędów described the soup in 1595 and Syreński in 1613, and in the seventeenth century it was one of the main soups of Poland, Lithuania and Ruthenia. Łuczaj, who has made it, found the ferment pleasantly sour after two days by a warm stove.

From the eighteenth century beetroot replaced hogweed in barszcz, and the hogweed soup survived mainly in Polesie and in a few Polish villages, the last recorded in Straconka in the 1940s or 1950s. Jundziłł in 1799 also noted that the leaves could be dried in the shade like celery and kept for later use.

Lookalikes

Common hogweed has dangerous relatives and neighbours. Giant hogweed, Heracleum mantegazzianum, has thick, bristly, purple-blotched stems that are hollow inside and can reach 5 m or more, with umbels up to 60 cm across. The RHS warns that young giant hogweed can be mistaken for the common species and that all four giant hogweed species carry high levels of furanocoumarins.

Poison hemlock, Conium maculatum, has smooth, hollow, bright green stems with red or purple spots, lacy fern-like leaves and a musty smell. Poison Control lists cow parsnip, angelica, wild chervil and wild carrot among the plants it is confused with, and says its poison, coniine, is present in every part.

Sap and skin

Hogweed sap contains furocoumarins, including bergapten, which make skin react to sunlight. DermNet describes streaked rashes after cutting the plant with a string trimmer that can last for months. With giant hogweed the RHS describes burning, blistering, pigmentation and long-lasting scarring after bare-skin contact.

The RHS advises washing any skin that touches the plant immediately, keeping it out of sunlight and seeking medical advice, and washing sap-stained clothes and tools carefully.

Gathering and storage

Syreński wrote that the leaves were commonly gathered in May. The historical sources describe two ways of keeping them: as a sour in water, and dried in the shade like celery. They give no storage times. Gathering should only follow certain identification with an experienced botanist or forager, with skin covered.

Open points

The sources read do not give an allergen assessment, a safe intake or a tested preservation method for the leaves. The identity of the plant Syreński called wodny barszcz, which he said was confused with the Polish barszcz, is not established. Rostafiński's 1916 monograph is cited here through Łuczaj's accounts.