Perennial Sowthistle — Sonchus arvensis — Family: Asteraceae — Aster

Perennial sowthistle is common in roadside and low maintenance turf and somewhat less common in landscapes. It prefers slightly alkaline or neutral soils, fine-textured, rich soils. Perennial sowthistle will not thrive on coarse sandy soils. The leaf shape resembles dandelion or chicory but has spines along the margin of the leaf. Perennial sowthistle spreads by rhizomes (tell-tale sign of perennial v. annual). The sparse leaves on the flower stalks are often entire (no lobes). The yellow flowers of sowthistle are similar to dandelion but are not solitary, hollow, or on a leafless stalk.

Also Known As...

• field sow thistle
• creeping sow thistle
• milk thistle
• corn sow-thistle
• swine-thistle
• tree sow-thistle
• dindle

Elongated	Notches	Upright

long yellow/green leaves from a rosette

rosette will branch before flowering

deeply lobed leaves with spines on the margin

yellow flowers on a branched stalk appearing in mid-to-late summer

all plant parts exude latex when broken

aggressive rhizomatous spreading habit

Perennial sowthistle is most often confused with other sowthistles and prickly lettuce.

At a glance, in a mowed situation where the plants are not flowering, perennial sowthistle may be mistaken for dandelion or chicory. Sowthistle has spines along the leaf margin which dandelion and chicory lack and sowthistle lacks spines on the midrib which are present on chicory.

Links:

• Chicory (Cichorium intybus)
• Dandelion (Taraxacum officinale)

Perennial sowthistle is not likely to establish in a dense, existing turf. It is more likely to be a weed in newly developed subdivisions where weed management tactics have not previously been employed. Due to its spreading rhizomatous habit, it can persist even after consistent mowing.

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