Charlock Sinapis arvensis

“Now is the time before the thistle blow,While gule is in the flower, and charlock breathesIts cloying scent around...”  - James Grahame, “British Georgics. June”   


A yellow-flowered wild mustard, charlock was once considered one of the most troublesome weeds of arable land. Its heads of bright yellow flowers are often to be seen on wasteland and roadsides. 

How to spot it

An erect branched and rather bristly plant with four-petalled yellow flowers borne in domed clusters. The leaves are toothed and irregularly lobed, narrower higher up the stem. Charlock is similar in appearance to White Mustard, which has more deeply lobed leaves and curved tips to its seed heads.

Where it grows

Charlock is abundant as a weed of cultivation and also found on roadsides, railways, tips and waste ground throughout the British Isles.

Best time to see

In flower from May to August.

How's it doing?

There has been little change its range, but it is easily controlled by herbicides, so is now less frequently seen in arable fields. The seeds are long-lived, and populations can readily re-appear on disturbed ground.

3 things you might not know

  • Oil can be extracted from the seed which has been used for lubricating machinery.
  • The leaves were once boiled and eaten.
  • It is also known as Charlock Mustard or Wild Mustard, and the seeds can be used to produce a mild mustard.