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Smooth Sow-thistle

Sonchus oleraceus

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Plant Profile

Flowering Months:
Asteraceae (Daisy)
Also in this family:
Alpine Blue Sow-thistle, Alpine Cotula, Alpine Fleabane, Alpine Saw-wort, Annual Ragweed, Annual Sunflower, Argentine Fleabane, Autumn Hawkbit, Autumn Oxeye, Beaked Hawksbeard, Beggarticks, Bilbao Fleabane, Black Knapweed, Black-eyed Susan, Blanketflower, Blue Fleabane, Blue Globe-thistle, Bristly Oxtongue, Broad-leaved Cudweed, Broad-leaved Ragwort, Brown Knapweed, Butterbur, Buttonweed, Cabbage Thistle, Canadian Fleabane, Canadian Goldenrod, Carline Thistle, Chalk Knapweed, Chamois Ragwort, Changing Michaelmas Daisy, Chicory, Chinese Mugwort, Chinese Ragwort, Coltsfoot, Common Blue Sow-thistle, Common Cat's-ear, Common Cudweed, Common Daisy, Common Dandelion, Common Fleabane, Common Goldenrod, Common Groundsel, Common Michaelmas Daisy, Common Mugwort, Common Ragwort, Common Wormwood, Coneflower, Confused Michaelmas Daisy, Corn Chamomile, Corn Marigold, Cornflower, Cotton Thistle, Cottonweed, Creeping Thistle, Daisy Bush, Dwarf Cudweed, Dwarf Thistle, Early Goldenrod, Eastern Groundsel, Eastern Leopardsbane, Elecampane, English Hawkweed, Fen Ragwort, Feverfew, Field Fleawort, Field Wormwood, Fox and Cubs, French Tarragon, Gallant Soldier, Garden Lettuce, Giant Butterbur, Glabrous-headed Hawkweed, Glandular Globe-thistle, Glaucous Michaelmas Daisy, Globe Artichoke, Globe-thistle, Goat's Beard, Golden Ragwort, Golden Samphire, Goldilocks Aster, Grass-leaved Goldenrod, Great Lettuce, Greater Burdock, Greater Knapweed, Grey-headed Hawkweed, Guernsey Fleabane, Hairless Blue Sow-thistle, Hairless Leptinella, Hairy Michaelmas Daisy, Harpur Crewe's Leopardsbane, Hawkweed Oxtongue, Heath Cudweed, Heath Groundsel, Hemp Agrimony, Highland Cudweed, Hoary Mugwort, Hoary Ragwort, Hybrid Knapweed, Intermediate Burdock, Irish Fleabane, Jersey Cudweed, Jerusalem Artichoke, Lance-leaved Hawkweed, Lavender-cotton, Leafless Hawksbeard, Least Lettuce, Leopardplant, Leopardsbane, Leptinella, Lesser Burdock, Lesser Hawkbit, Lesser Sunflower, London Bur-marigold, Magellan Ragwort, Marsh Cudweed, Marsh Hawksbeard, Marsh Ragwort, Marsh Sow-thistle, Marsh Thistle, Meadow Thistle, Melancholy Thistle, Mexican Fleabane, Milk Thistle, Mountain Everlasting, Mouse-ear Hawkweed, Musk Thistle, Narrow-leaved Cudweed, Narrow-leaved Hawkweed, Narrow-leaved Michaelmas Daisy, Narrow-leaved Ragwort, New England Hawkweed, New Zealand Holly, Nipplewort, Nodding Bur-marigold, Northern Hawksbeard, Norwegian Mugwort, Oxeye Daisy, Oxford Ragwort, Pearly Everlasting, Perennial Cornflower, Perennial Ragweed, Perennial Sow-thistle, Perennial Sunflower, Pineapple Mayweed, Plantain-leaved Leopardsbane, Ploughman's Spikenard, Plymouth Thistle, Pontic Blue Sow-thistle, Pot Marigold, Prickly Lettuce, Prickly Sow-thistle, Purple Coltsfoot, Rayed Tansy, Red Star Thistle, Red-seeded Dandelion, Red-tipped Cudweed, Robin's Plantain, Roman Chamomile, Rough Cocklebur, Rough Hawkbit, Rough Hawksbeard, Russian Lettuce, Safflower, Salsify, Saw-wort, Scented Mayweed, Scentless Mayweed, Sea Aster, Sea Mayweed, Sea Wormwood, Seaside Daisy, Shaggy Mouse-ear Hawkweed, Shaggy Soldier, Shasta Daisy, Shetland Mouse-ear Hawkweed, Shrub Ragwort, Sicilian Chamomile, Silver Ragwort, Slender Mugwort, Slender Thistle, Small Cudweed, Small Fleabane, Smooth Cat's-ear, Smooth Hawksbeard, Sneezeweed, Sneezewort, Spear Thistle, Spotted Cat's-ear, Spotted Hawkweed, Sticky Groundsel, Stinking Chamomile, Stinking Hawksbeard, Tall Fleabane, Tall Mouse-ear Hawkweed, Tansy, Thin-leaved Sunflower, Treasureflower, Trifid Bur-marigold, Tuberous Thistle, Tyneside Leopardplant, Viper's Grass, Wall Lettuce, Welsh Groundsel, Welted Thistle, White African Daisy, White Butterbur, White Buttons, Willdenow's Leopardsbane, Winter Heliotrope, Wood Burdock, Wood Ragwort, Woody Fleabane, Woolly Thistle, Yarrow, Yellow Chamomile, Yellow Fox and Cubs, Yellow Oxeye, Yellow Star Thistle, Yellow Thistle, York Groundsel
Life Cycle:
Maximum Size:
150 centimetres tall
Fields, gardens, grassland, meadows, mountains, roadsides, rocky places, sand dunes, towns, walls, wasteland, waterside.

Yellow, many petals
Pale yellow dandelion-like flowers in clusters, up to 2.5cm wide.
A cylidrical, light brown, wrinkly achene (seed) with white fluffy pappas (hairs) at one end. The fruits are single-seeded.
The dark green leaves are deeply divided into triangular-shaped lobes and have irregularly toothed margins. They are less prickly-edged than Prickly Sow-thistle and more bluish-green in colour. The leaves are arranged alternately along the stems.
Sometimes faintly aromatic.
Other Names:
Annual Sow-thistle, Colewort, Common Milk Sow-thistle, Common Sow-thistle, Hare's Lettuce, Hare's Thistle, Milkweed, Milky Tassel, Soft Thistle, Swinies.
Frequency (UK):

Other Information


Sonchus oleraceus, also known as "common sowthistle" or "smooth sowthistle," is a perennial herb that is native to Europe and Asia. It is a hardy plant that can grow in a variety of soil types and can tolerate shade and dry conditions. It can be found in grasslands, meadows, along roadsides and in croplands. It is considered as a weed in some regions, and it can be difficult to control as it reproduces both by seed and underground rhizomes. The plant has large leaves and yellow flowers that can reach up to 3-4 feet tall. The leaves and flowers are edible, but they are not commonly used as food. It has been used in traditional medicine to treat various ailments such as skin irritations and infections.


Smooth sow-thistle, also known as Sonchus oleraceus, is a common weed found in many parts of the world. While it is often considered a nuisance in gardens and agricultural fields, it also has a rich history of use in traditional medicine and as a food source.

Appearance and Habitat

Smooth sow-thistle is an annual or biennial plant that can grow up to 5 feet tall. Its leaves are deeply lobed and can grow up to 10 inches long, with spiny edges. The plant produces small, yellow flowers that resemble dandelion flowers, and it produces fluffy, white seeds that are dispersed by the wind.

Smooth sow-thistle is native to Europe but has become naturalized in many other parts of the world, including North America, South America, and Australia. It can grow in a variety of habitats, including gardens, agricultural fields, and along roadsides.

Traditional Uses

Smooth sow-thistle has a long history of use in traditional medicine, particularly in Europe and Asia. The plant has been used to treat a variety of ailments, including liver and kidney problems, digestive issues, and respiratory conditions. It has also been used as a diuretic and to promote wound healing.

In addition to its medicinal properties, smooth sow-thistle has also been used as a food source in many cultures. The young leaves can be eaten raw or cooked, and the stems can be cooked and eaten like asparagus. The plant has a slightly bitter taste, similar to other leafy greens like spinach and arugula.

Modern Research

While there is limited scientific research on the medicinal properties of smooth sow-thistle, some studies have shown that it may have antioxidant and anti-inflammatory properties. In addition, the plant contains several compounds that have been shown to have potential anticancer effects.

Despite its potential health benefits, it is important to exercise caution when using smooth sow-thistle. The plant is known to contain compounds that can cause allergic reactions in some people, and it may interact with certain medications.

Control and Management

While smooth sow-thistle has some potential benefits, it is also considered a noxious weed in many parts of the world. The plant can spread quickly and compete with other plants for resources, making it a problem for farmers and gardeners.

To control smooth sow-thistle, it is important to remove the plants before they produce seeds. This can be done by hand-pulling the plants or using herbicides. Preventing the plants from establishing in the first place is also important, and can be done by maintaining healthy soil and using mulch or other ground covers to prevent the seeds from germinating.

Smooth sow-thistle is a common weed that has both traditional and modern uses. While it may have some potential health benefits, it is important to exercise caution when using the plant, and to control its spread in agricultural and garden settings.

More Information

Smooth sow-thistle is a member of the Asteraceae family, which includes many other common plants like dandelions, sunflowers, and asters. The plant's scientific name, Sonchus oleraceus, is derived from the Greek word "sonchus," meaning "hollow stem," and the Latin word "oleraceus," meaning "vegetable" or "edible."

Smooth sow-thistle is an important food source for a variety of insects, including bees, butterflies, and moths. The plant's seeds are also eaten by birds and small mammals, and the leaves and stems are grazed by livestock in some parts of the world.

In addition to its traditional medicinal uses, smooth sow-thistle has also been studied for its potential as a natural insecticide. Some studies have shown that extracts from the plant may be effective against common garden pests like aphids and spider mites.

Smooth sow-thistle is a fascinating plant with a long history of use in traditional medicine and as a food source. While it can be a nuisance in certain settings, it also plays an important role in many ecosystems and may have potential benefits for human health and agriculture.

Smooth sow-thistle is a common weed that can be found in many different habitats around the world. It is often considered a problem for farmers and gardeners, as it can quickly spread and outcompete other plants. However, there are several ways to manage and control the spread of this plant.

One approach to controlling smooth sow-thistle is to use cultural methods, such as regular weeding, mulching, and improving soil health. These methods can help prevent the plant from establishing in the first place, and can also reduce the overall weed pressure in a garden or agricultural field.

Chemical control methods, such as herbicides, can also be effective at managing smooth sow-thistle. However, it is important to follow the instructions on the label carefully and apply the herbicide at the appropriate time to avoid damaging other plants or contaminating nearby water sources.

Biological control methods, such as introducing natural enemies of the plant, can also be effective at controlling its spread. However, this approach is generally more complex and requires careful consideration to avoid unintended consequences.

Smooth sow-thistle is a fascinating plant with a rich history of use in traditional medicine and as a food source. While it may be considered a nuisance in some settings, it also plays an important ecological role and may have potential benefits for human health and agriculture.

Smooth sow-thistle has a number of interesting adaptations that have helped it survive and thrive in different environments. For example, its deeply lobed leaves help to reduce water loss by increasing surface area for photosynthesis while minimizing exposure to sunlight.

The plant's hollow stem also allows for greater flexibility and resistance to wind and other environmental stresses. Additionally, smooth sow-thistle has a well-developed root system that can help it access water and nutrients in challenging soil conditions.

Smooth sow-thistle has been used as a traditional medicine for centuries, and modern research has confirmed that it contains a number of bioactive compounds with potential health benefits. For example, the plant has been shown to have antioxidant and anti-inflammatory properties, which may help to protect against chronic diseases such as cancer, heart disease, and Alzheimer's disease.

Smooth sow-thistle also contains several compounds that have shown promise as natural insecticides, which could have important implications for sustainable agriculture. However, more research is needed to fully understand the potential uses and risks of this plant.

In conclusion, smooth sow-thistle is a fascinating plant with a long history of use in traditional medicine and as a food source. While it can be a nuisance in some settings, it also has important ecological roles and potential benefits for human health and agriculture. As with any plant, it is important to exercise caution and use appropriate management strategies to avoid unintended consequences.


Smooth Sow-thistle filmed in Rivington, Lancashire on the 11th June 2023.


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Reproduced by kind permission of the BSBI.

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