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Summary
Canada thistle is a perennial, aggressively spreading thistle widely regarded as one of the most troublesome weeds in North America. Despite its reputation, it is edible and shares many of the same food qualities as other true thistles, particularly in its young shoots, peeled stems, and roots. Unlike most Cirsium species, Canada thistle spreads by rhizomes rather than relying on a biennial taproot strategy. This growth habit makes it persistent, abundant, and difficult to eradicate—traits that can work in a forager’s favor when edible parts are properly harvested. However, documentation of its use as food is surprisingly sparse, and its roots are generally thinner and less rewarding than those of biennial thistles. Bloom Color: Pink, Purple.
Main Bloom Time: Early summer, Late summer, Mid summer. Form: Irregular or sprawling.
Physical Characteristics
Cirsium arvense is a PERENNIAL growing to 0.9 m (3ft) by 1 m (3ft 3in) at a fast rate.
See above for USDA hardiness. It is hardy to UK zone 4 and is not frost tender. It is in flower from July to September, and the seeds ripen from August to October. The species is hermaphrodite (has both male and female organs) and is pollinated by Bees, flies, Lepidoptera (Moths & Butterflies), beetles. The plant is self-fertile.
Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It cannot grow in the shade. It prefers moist soil.
UK Hardiness Map
US Hardiness Map
Synonyms
Carduus arvensis. Serratula arvensis.
Plant Habitats
Meadow; Cultivated Beds;
Edible Uses
Edible Parts: Leaves Oil Root Stem
Edible Uses: Curdling agent Oil
Root of first year plants - raw or cooked[183]. Nutritious but rather bland, they are best used in a mixture with other vegetables[9]. The root is likely to be rich in inulin, a starch that cannot be digested by humans. This starch thus passes straight through the digestive system and, in some people, ferments to produce flatulence[K]. Stems - they are peeled and cooked like asparagus or rhubarb[9, 12, 177, 183]. Leaves - raw or cooked[177, 183]. A fairly bland flavour, but the prickles need to be removed before the leaves can be eaten - not only is this rather fiddly but very little edible leaf remains[K]. The leaves are also used to coagulate plant milks etc[46, 61, 183]. Foraging notes. Edible but inferior to biennial thistles, best used for young shoots and stems rather than roots. Edible Uses & Rating: Young shoots and peeled stems are the most practical edible parts of Canada thistle. Roots are technically edible but are usually thin, fibrous, and low in starch compared to biennial thistles, making them a secondary resource at best. Leaves are edible only after extensive trimming and cooking and are generally not worth the effort. Overall, Canada thistle ranks as a moderate- to low-value wild food, valuable primarily due to its abundance rather than superior quality [2-3]. Taste, Processing & Kitchen Notes: Peeled young stems are mild, slightly sweet, and comparable to celery, though usually more fibrous. Cooking softens the texture but does not fully eliminate stringiness. Roots lack the rich starchiness of biennial thistles and tend to be woody or hollow, with a mild but unimpressive flavor. Leaves are bitter and spiny and do not improve much with cooking. Shoots harvested very early in the season are the best-tasting part of the plant [2-3]. Seasonality (Phenology): Young shoots and stems are best harvested in early spring as new growth emerges. Roots may be harvested year-round but are best in late autumn or early spring when carbohydrate reserves are highest. Flowering occurs from late spring through summer. Safety & Cautions (Food Use): Spines pose a physical hazard. Roots may contain bitter resins that can cause digestive discomfort in sensitive individuals if eaten in quantity. Harvest & Processing Workflow: Harvest young shoots in early spring. Peel thoroughly to remove spines and outer fibers. Cook or eat fresh. Roots should be cleaned carefully, sliced thinly, and boiled to improve texture and flavor [2-3]. Cultivar/Selection Notes: No cultivars exist. Considerable variation occurs among populations. Look-Alikes & Confusion Risks: Other Cirsium species are similar and generally edible in similar ways. Avoid confusing with Centaurea species, which lack edible roots and stems. Traditional / Indigenous Use Summary: Canada thistle was reportedly eaten by some Indigenous groups, though documentation is sparse compared to native biennial thistles. Its use appears opportunistic rather than staple-based [2-3].
References More on Edible Uses
Medicinal Uses
Plants For A Future can not take any responsibility for any adverse effects from the use of plants. Always seek advice from a professional before using a plant medicinally.
Antiphlogistic Astringent Diuretic Emetic Emmenagogue Hepatic Tonic
The root is tonic, diuretic, astringent, antiphlogistic and hepatic[207]. It has been chewed as a remedy for toothache[4]. A decoction of the roots has been used to treat worms in children[257]. A paste of the roots, combined with an equal quantity of the root paste of Amaranthus spinosus, is used in the treatment of indigestion[272]. The plant contains a volatile alkaloid and a glycoside called cnicin, which has emetic and emmenagogue properties[240]. The leaves are antiphlogistic[207]. They cause inflammation and have irritating properties[207[.
References More on Medicinal Uses
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Other Uses
Oil Tinder
The seed fluff is used as a tinder[106]. The seed of all species of thistles yields a good oil by expression[4]. The seed of this species contains about 22% oil[240]. Dynamic accumulator.
Special Uses
Dynamic accumulator Food Forest
References More on Other Uses
Cultivation details
Canada thistle is edible but unexceptional. Its greatest value lies in its abundance rather than its flavor or nutrition. When better thistles are unavailable, it can serve as a serviceable substitute. The creeping thistle is a pernicious garden weed, spreading freely from its aggressive root system[17, K], It can quickly form dense clumps of growth and really does not need to be introduced into the garden. Succeeds in any ordinary garden soil in a sunny position[200]. Plants are often dioecious[17]. A polymorphic species[17]. Special Features:North American native, Invasive, Attracts butterflies. In garden design, as well as the above-ground architecture of a plant, root structure considerations help in choosing plants that work together for their optimal soil requirements including nutrients and water. The root pattern is fleshy. Thick or swollen - fibrous or tap root [2-1]. Growing Conditions: Canada thistle thrives in disturbed soils, agricultural fields, roadsides, riparian areas, and open grasslands. It tolerates a wide range of soil types and moisture conditions and spreads aggressively in fertile soils. Habitat & Range: Native to Europe and Asia, Canada thistle is now widespread throughout North America, including much of the Southwest, though it is more common at higher elevations and in irrigated or moist areas. Size & Landscape Performance: Plants typically reach 0.5–1.5 meters tall. Colonies can cover large areas due to extensive rhizome networks. It is one of the most persistent perennial weeds in North America. Cultivation (Horticulture): Canada thistle is never intentionally cultivated and is actively controlled or eradicated where possible. Its aggressive nature makes it unsuitable for intentional planting. Pests & Problems: Few natural predators effectively limit its spread. Biological control insects exist, but rarely eliminate populations. Pollination: Pollinated primarily by bees and other generalist insects. Identification & Habit: Canada thistle forms dense colonies through underground rhizomes, producing multiple upright stems from a shared root system. Leaves are deeply lobed, sharply spined, and arranged alternately along the stems. Unlike many native thistles, the plants are often narrower and more uniform in appearance. Flower heads are relatively small, discoid, and purple, borne in clusters rather than singly. Male and female flowers often occur on separate plants. The rhizomatous habit is the most important distinguishing feature, as most other southwestern thistles rely on taproots rather than creeping underground stems. FAMILY: Sunflower family (Asteraceae) – Cirsium genus. COMMON NAMES: Canada thistle, field thistle, creeping thistle. USDA Hardiness Zones: Approx. Zones 3–8. Typical Size: 30–150 cm tall; spreading perennial with extensive rhizomes.
References Carbon Farming Information and Carbon Sequestration Information
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Plant Propagation
Seed - sow early spring or autumn in situ. Germination usually takes place within 2 - 8 weeks at 20°c. A pernicious weed, not many people would want to invite this plant into their garden.
Other Names
If available other names are mentioned here
Creeping thistle
Field thistle, Californian thistle, Canadian thistle, lettuce from hell thistle, corn thistle, cursed thistle, field thistle, green thistle, hard thistle, perennial thistle, prickly thistle, small-flowered thistle, way thistl, Cardo cundidor, Choussio, Ciji, Da khawarak azghai, Honghuamiao,Koygocerten, Koygocuren, Ohakas, Ohtja, Perticone, Stioppone, Stramontano.
Native Range
TEMPERATE ASIA: Afghanistan, Iran, Turkey, Russian Federation-Ciscaucasia (Ciscaucasia), Armenia, Azerbaijan, Georgia, Russian Federation (Dagestan), Russian Federation-Western Siberia (Western Siberia), Russian Federation-Eastern Siberia (Eastern Siberia), Turkmenistan, Mongolia, Russian Federation (Habarovskij kraj, Primorye, Amur, Magadanskaja oblast, Sakhalin), China (Anhui Sheng, Beijing Shi, Fujian Sheng, Gansu Sheng, Guizhou Sheng, Hebei Sheng, Heilongjiang Sheng, Henan Sheng, Hubei Sheng, Hunan Sheng, Jiangsu Sheng, Jiangxi Sheng, Jilin Sheng, Liaoning Sheng, Nei Mongol Zizhiqu, Ningxia Huizi Zizhiqu, Qinghai Sheng, Shaanxi Sheng, Shandong Sheng, Shanghai Shi, Shanxi Sheng, Sichuan Sheng, Tianjin Shi, Xinjiang Uygur Zizhiqu, Xizang Zizhiqu, Zhejiang Sheng) TROPICAL ASIA: India (Bihar, Himachal Pradesh, Jammu and Kashmir, Punjab, Uttar Pradesh, West Bengal), Nepal EUROPE: Denmark, Finland, United Kingdom, Ireland, Norway, Sweden, Austria, Belgium, Switzerland, Czech Republic, Germany, Hungary, Netherlands, Poland, Slovakia, Russian Federation (European part), Belarus, Estonia, Lithuania, Latvia, Moldova, Ukraine (incl. Krym), Albania, Bulgaria, Bosnia and Herzegovina, Greece, Croatia, Italy (incl. Sardinia, Sicily), North Macedonia, Montenegro, Romania, Serbia, Slovenia, Spain (incl. Baleares), France (incl. Corsica), Portugal
Weed Potential
Right plant wrong place. We are currently updating this section.
Please note that a plant may be invasive in one area but may not in your area so it's worth checking.
Extremely high. Canada thistle is considered noxious in many regions and is notoriously difficult to eradicate once established. Widely considered a weed even where it is native. It is cited as a noxious weed in several countries; for example Australia, Brazil, Canada, Ireland, New Zealand, and the United States.
Conservation Status
IUCN Red List of Threatened Plants Status : This taxon has not yet been assessed.
Growth: S = slow M = medium F = fast. Soil: L = light (sandy) M = medium H = heavy (clay). pH: A = acid N = neutral B = basic (alkaline). Shade: F = full shade S = semi-shade N = no shade. Moisture: D = dry M = Moist We = wet Wa = water.
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(L.)Scop.
Botanical References
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