The healing power of common pig grass

Common pig grass is an annual herb. The stems, seeds and leaves of this plant can be eaten as vegetables, both raw and cooked. It is also possible to prepare a tea from this plant. Pig grass does not grow higher than 30 centimeters. It even grows flat on the ground. This herb originally comes from Europe and the temperate parts of Asia. The best known thing about pig grass is the fact that it has been a medicinal plant for many years. It is mainly used for sore throat, diarrhea, white discharge, gout and bleeding wounds. NB! This article is written from the personal view of the author and may contain information that is not scientifically substantiated and/or in line with the general view.

Botanical drawing of pig grass / Source: Carl Axel Magnus Lindman, Wikimedia Commons (Public domain)


  • Origin myth of pig grass
  • Traditional use of pig grass
  • Naming
  • Active substances
  • Pig grass, good for the throat and respiratory tract
  • Pig grass, good for internal problems
  • Unconfirmed effects
  • Dose and safety

Origin myth of pig grass

In Dutch, pig grass used to be called ‘Hannes-aan-de-weg’. How did the plant get this name? In a small village once lived a boy named Hannes who was in love with the daughter of a rich farmer. Her name was Gretel. Hannes had a poor father. Grietje’s rich father forbade his daughter to meet Hannes. Grietje was not allowed to go out into the street and looked longingly at Hannes from her window. He stood in front of the house. He stood guard there because one day Gretel would have to come out, or so he thought. But the farmer persisted and Grietje was confined to the house. They just wait and wait. At one point they waited so long that they turned into a flower. Grietje became the lady-in-the-green and her great love became Hannes-aan-de-weg, which was also known as a popular herb for pigs; pig grass.

Traditional use of pig grass

Pig grass is one of the oldest medicinal herbs known to man. In the past, this medicinal plant was often used for consumption, which is now better known as tuberculosis or TB. In traditional folk medicine, a tea of the whole herb is drunk for kidney and stomach problems. In the Middle Ages, pig grass was used for snake bites. One should never pluck the plant with the right hand, otherwise it will lose its strength. A piece of pig grass was worn around the neck against ‘third-day fever’, which was the name for malaria. Malaria was given the name third-day fever because an attack of fever occurs every 48 hours. In addition, people drank the juice, but not for its medicinal effectiveness. In the past, men thought that if they drank pig grass juice they could converse a lot with women.


In Latin, common pig grass is called Polygonum aviculare . Dutch has a number of alternative names for this medicinal plant: Pig grass, Bird knotweed, Barge grass, Knot grass, Moth grass, Knob grass, Bloodwort, Hannes-aan-de-weg, Gers and Peat grass. Polygonum is a compound of poly which means ‘many’ and gonum which stands for ‘corner’. Polygonum therefore means ‘polygonal’. If you look at the growth habit of pig grass, you will understand why pigs belong to this species. Aviculare is a combination of the words avi, which means ‘bird’ and culare. What does ‘world’ stand for? It is so called because birds like the grass. Some bird owners give this herb to a bird in a cage. The Dutch name bird knotweed is a reference to the Latin name. Bloodwort is a name that refers to the haemostatic activity of pig grass. In English the plant is called knotweed or knapweed. In German the plant is called Vogelkn√∂terich.

Active substances

The entire herb of pig grass is used for phytotherapeutic purposes. This herb contains the following active substances: two types of silicic acid, both water-soluble silicic acid and water-insoluble silicic acid. It also contains tannins, mucilages, flavonglycosides such as avicularin and anthraquinone derivatives.

Pig grass, good for the throat and respiratory tract

Pig grass is a natural source of soluble silicic acid or silicon. It is therefore a plant that is good for supplementing the mineral balance in humans. Silicic acid is a substance that strengthens connective tissue. Furthermore, pig grass has a mild expectorant function. This means that it promotes the release of mucus. Tannins have an astringent effect. Due to the combination of these medicinal activities, pig grass is used in phytotherapy for the following indications:

Flower of the Polygonum aviculare / Source: Dalgial, Wikimedia Commons (CC BY-SA-3.0)

  • Laryngeal inflammation,
  • A sore throat,
  • Chronic respiratory diseases,
  • Bronchitis.

When cows eat a lot of pig grass, the milk turns blue.

Pig grass, good for internal problems

The astringent effects of the tannins or tannins in common pig grass are useful for internal use. Pig grass can be eaten as a vegetable, so internal use is safe. Herbalists may decide to prescribe it for one of the following indications related to digestion:

  • Diarrhea,
  • Enteritis or intestinal mucosal inflammation,
  • Hemorrhoids,
  • Leucorrhea or white tide.

Unconfirmed effects

The effects described above have been confirmed by science, but there are a number of activities that have not yet been investigated by science. For example, it is said to be good for rheumatic conditions because it has a depurative effect and is a diuretic. Other unproven effects of pig grass are:

Polygonum aviculare / Source: Rasbak, Wikimedia Commons (CC BY-SA-3.0)

  • Antidiabetes effect,
  • Strengthening blood vessels,
  • haemostatic effect,
  • Laxative effect,
  • Calming effect,
  • Adjuvant for tuberculosis.

Dose and safety

There are three ways to use this safe medicinal plant.

  • Dried herb: 4 to 6 grams per day.
  • Mother tincture: 40 drops three times a day,
  • Decoct, tea: 2 to 4 cups of a dessert spoon of herb per cup, boil for two minutes and then let stand for 20 minutes.