Yellow Dock, also known as Curled Dock, forms a basal rosette of pointed, oval, wavy-edged leaves which can grow up to 25cm long, followed by several erect stems up to 1.5 m tall. The name is Latin for Curly Sorrel (Crispus meaning curly and referring to the curled leaf margins).
Although many people class dock as a weed, this extremely large leafed species of the buckwheat family is edible and has many medicinal uses. Cutting back (aka harvesting) any seed heads will ensure it does not spread, as will care taken when digging up roots for harvest. The tap root can be 3m deep and so will regrow as the sole plant, you just need to ensure you don’t drop other small pieces of root which could take hold and start a new plant.
The leaves are a good source of Vitamins A and C, plus iron and potassium, and can be used as a vegetable. Consuming the younger leaves is advisable as they will be less bitter than older ones, and although they can be used fresh, boiling first in a couple of changes of water will leach out some of the oxalic acid. In either case consume in moderation only (as with other related leafy greens such as silverbeet and sorrel). The leaves can also be dried and stored.
The seeds are also edible and the pods so fine they can just be ground up with the seeds so do not need to be winnowed. The flour is said to taste like buckwheat, perhaps slightly more bitter.
The plant has a long history of domestic herbal use as a gentle and safe laxative. It is can also be used to treat anemia (often alongside nettle), and makes a useful non-constipating iron supplement. It can also be taken either internally or externally to relieve various skin conditions. In homeopathy it is used to treat respiratory conditions. All parts of the plant can be used but the roots are most active medicinally. They can be dried after harvest for later use.
Being a tap rooted plant, dock draws up a range of nutrients present in the sub-soil and recycles them via the leaves to the topsoil, or leaves can be added to your compost heap or liquid fertilisers. The huge leaves of this species make them particularly useful for this purpose, and for biomass collection and chop and drop mulching systems.
Yellow, dark green to brown and dark grey dyes can be obtained from the roots. They do not need a mordant.
Yellow dock is readily eaten by cattle and pigs and small quantities may provide useful nutrients. Large quantities may cause oxalate poisoning (as in humans) but field cases of toxicity are apparently rare. May cause dermatitis in horses and sheep.
Grows in a wide range of conditions from sandy to clay soil and full sun to partial shade, but does prefer some moisture. Frost hardy. Perennial.
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