Prickly Sow-thistle

An uncommon annual weed of disturbed soils, newly sown areas and neglected lawns, but not of well-maintained turf surfaces. Mowing a surface should be enough to prevent this weed from becoming established. It produces a well-developed tap root, whilst the leaves have distinctly prickly margins, with the leaf base often clasping the stem, the upper leaf surface being smooth and relatively shiny. It flowers from June to October, having yellow flower heads up to about 20mm in diameter, but this is variable, although these would not normally be seen in a turf situation. It will grow in a range of soil conditions, from dry to moist, although preferring a more neutral, not acidic, soil pH, in open, not shaded, conditions. It is also called Rough Sow-thistle, and its scientific name is Sonchus asper.