Sweet Coltsfoot, Japanese sweet coltsfoot, Butterbur

Petasites japonicus

Physical Characteristics

Petasites japonicus is a PERENNIAL growing to 0.6 m (2ft) by 1.5 m (5ft in) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 5. It is in flower in February, and the seeds ripen in March. The species is dioecious (individual flowers are either male or female, but only one sex is to be found on any one plant so both male and female plants must be grown if seed is required). and is pollinated by Insects. The plant is not self-fertile. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in full shade (deep woodland) semi-shade (light woodland) or no shade. It prefers moist or wet soil.

Distribution

E. Asia - China, Japan, Korea. Naturalized in Britain.

Habitats

Woodland Garden Sunny Edge; Dappled Shade; Shady Edge; not Deep Shade; Ground Cover; Meadow; Bog Garden;

Edible Uses

Edible Parts: Flowers Stem Edible Uses: Leaf stalks - cooked and used like rhubarb[1, 2, 46, 116]. The stems can be up to 1.2 metres long[104]. They can be boiled and seasoned, pickled and used in winter soups or preserved in miso[183]. They can be boiled, dipped in cold water then peeled and baked - they have a pleasant fragrant taste[206]. Flower buds cooked or used as a flavouring[1, 22, 46, 61, 105]. A slightly bitter yet agreeable flavour[116, 206], they are much prized in Japan[183]. They can be eaten whilst still green with miso or boiled down in soy sauce[183]. The young flowering stems can be eaten cooked[206].

Medicinal Uses

Antiasthmatic Antispasmodic Expectorant Miscellany Poultice The plant (though the exact part of the plant used is not specified) is antiasthmatic, antispasmodic, expectorant and poultice[147]. A decoction is used in the treatment of chronic coughing and pulmonary 'deficiency', laboured or difficult breathing and asthma, constant sputum formation and pulmonary tuberculosis[147].

Known Hazards

None known