Growth Habit: Hedge mustard is a moderately competitive plant. Its hard, wiry stems which grow erect, with very short internodes, can reach up to 1m. TBasal leaves form a deeply divided rosette (a cluster of leaves at the base of a plant often lying flat against the ground). The basal (lower) leaves are up to 10cm long, pinnatisect (cut into lobes on both sides of the midrib to or almost to the midrib) with 3-5 pairs of toothed lobes and a large terminal lobe petiolate (with a leaf stalk). Middle and upper stem leaves are smaller, with or without a short petiole, much less divided, alternate (1 leaf per node). The whole plant often appears grey-green in appearance.
Type of Plant: This weed is an annual, initially forming a rosette.
Flowers: Hedge mustard has 4 petalled, yellow flowers, 3-4mm in diameter. These are arranged in clusters.
Fruit/Seed: Seeds are housed in seed pods 10-20mm in length. These are located close and parallel to the stem. Several hard brown seeds are contained in each pod. All plants in the genus Sisymbrium have fruit (siliqua) without a beak and the seeds are in one row. For S. officinale, the fruit is held tightly alongside the stem and is only 1-2cm long.
Dispersal: Reproduces from seed. Seed is mainly dispersed by soil movement and by machinery, particularly harvesters.
Distribution: Found in waste places, roadsides, orchards, cereal and vegetable crops.
Status: Undeclared in Tasmania.
- Can be a significant weed of crops, particularly brassica crops such as canola.
- Suspected of tainting milk.
For further information contact the Department of Primary Industry, Water and Environment, Tasmania.
- Grubbing (all year). Isolated plants may be manually removed with a fork or similar tool.
- Herbicide (autumn, winter and spring). Herbicides registered in Tasmania include metsulfuron, glyphosate, dicamba, MCPA and mecoprop. Consult the D.P.I.W.E. for more specific information if the weed is in a crop.
N.B. Always check the herbicide label before use.