Hairy Brassica, Hoary Mustard Hirschfeldia

Buchan Weed (Hirschfeldia incana).

Buchan Weed aka Hairy Brassica, and Hoary Mustard is known as Short Pod Mustard in the USA. It is an annual or biennial (sometimes perennial), herb that grows up to 100 cm tall and has pale yellow flowers. It is found in the ACT, NSW, QLD, SA, TAS, VIC, and WA.

After you read this, you will be able to:

  • Identify capeweed Buchan Weed, Hairy Brassica, and Hoary Mustard.
  • Know the habitat of Buchan Weed, Hairy Brassica, and Hoary Mustard.
  • Know the best options to control Buchan Weed, Hairy Brassica, and Hoary Mustard

Seeds germinate through the Autumn, and these grow slowly until mid-winter when flowering stems develop. It flowers from September to February.



How to Identify Buchan Weed.

Hoary Mustard has a slender, deep taproot with branching laterals in the top 300 mm of soil.

Category: Herb.

Flower: Flowers consist of four pale purple veined yellow petals, and each petal is 6-9 mm long.
Height: Bushan Weed can grow up to 100cm tall.
Leaf length: The lower leaves are up to 350 mm long, deeply lobed to the stem. The upper leaves look the same as the lower leaves, but are smaller, diminishing in size, and number.
Reproduction: Hairy Brassica only reproduces by seed, that is spread by water, and human activity.

Comments: The stems and leaves have a cover of stiff, simple bristle-like hairs.

Habitat: Buchan Weed is an indicator weed of dry or moist soil, and thrives under warm conditions in N rich soils.

More on lawn and turf grass weeds is in our weed ID chart.




How to control Buchan Weed.

Both cultural and chemical control control Hoary Mustard in your lawn and turf.

Cultural control:

Dense healthy turfgrass helps prevents this weed from establishing. You can pull individual plants out by hand, but you must take care to remove as much of the taproot as possible. This is because plants are able to re-shoot from pieces of root left in the soil.




Chemical control:

Non selective options include Glyphosate (Rapid Fire 800). If you use this and water quality is an issue then we recommend the use of ProForce Manta Ray.