March to November and all year round in mild winters.
It is found throughout the country.
For a map see the National Biodiversity Network Gateway
It is found on disturbed ground in grassland, brownfield sites
and waste tips, around ploughed fields, and alongside roads,
foot paths and coastal earth dykes.
It is a garden and agricultural weed.
Smooth Sow-thistle is a very variable, annual herb that can
grow up to 2m.
Flowers are pale yellow (2-2.5cm across) in flower heads.
Leaves are variably prickly and have a greyish tinge (leaf 2).
They have pointed auricles at the site of attachment to the stems.
It is similar to Prickly Sow-thistle, which also appearing in March
in similar habitats, but it is generally more common, greyer and
with different auricles.
Both plants are variably prickly, ranging from few prickles to
prickly all over.
Usually, Prickly Sow-thistle has most prickles.
Pointed leaf auricles