Cirsium tuberosum

(L.) All.

Tuberous thistle

AsteraceaeRoots

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(c) Simon Crameri, some rights reserved (CC BY-NC), uploaded by Simon Crameri

iNaturalist · cc-by-nc
(c) janek42, some rights reserved (CC BY-NC)

What to Eat

Edible parts: Root

The root is edible cooked and can be stored overwinter. It has a slight bitterness but is acceptable as a cooked vegetable. Occasionally the root is very aromatic, which makes it less pleasant to eat. The root is rich in inulin, a starch the human body cannot digest, which passes straight through the digestive system and may ferment in some people, causing flatulence.

Where to Find It

It is a temperate plant.

Britain, Europe,

Countries: Andorra, Albania, Austria, Bosnia & Herzegovina, Belgium, Bulgaria, Belarus, Switzerland, Cyprus, Czechia, Germany, Denmark, Estonia, Spain, Finland, France, United Kingdom, Greece, Croatia, Hungary, Ireland, Iceland, Italy, Liechtenstein, Lithuania, Luxembourg, Latvia, Monaco, Moldova, Montenegro, North Macedonia, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Russia, Sweden, Slovenia, Slovakia, San Marino, Ukraine

How to Identify

Tuberous thistle is a perennial growing 0.6 m tall that flowers from June to August with seed ripening July to September. It thrives in light sandy, medium loamy, and heavy clay soils across a range of pH levels from mildly acidic to mildly alkaline, requiring full sun and moist conditions.

How to Grow

Propagation: Sow seed in early spring or autumn in situ. Germination typically occurs within 2–8 weeks at 20°C. Division in spring or autumn is also possible and very easy — larger clumps can be replanted directly into permanent positions, while smaller clumps are best potted up and grown on in a cold frame until rooting well, then planted out in summer or the following spring.