Annual sow thistle



Scientific Name

Sonchus oleraceus L.

Common Names

Annual Sow Thistle



•    Overview:

Sow thistle is a competitive plant that grows rapidly following recent rainfall; it is able to produce seed from a very early growth stage and can produce about 6000 seeds which remain viable for several years. This broadleaf weed can be extremely difficult to control.

•    Scouting:
Main description:
Defining features are light yellow to greenish flowers which bloom from June through to October, erect stems that when cut secrete a white liquid that is thicker in viscosity then that of water. Seeds are dispersed through the development of a puff ball that it is located at the end of stem.

Cotyledon: Cotyledons young leaves are alternate and oval shape, they have petiolate and immature plant is light green colour.

Mature plant: Initial leaves are nearly round in shape, with fine indentations Leaves are greenish blue in colour. Outer edges of mature leaves are slightly prickly. Stems are thick and erect and mature plant can grow up to 100cms in height.

•    Methods of control (including products):
Velocity (seedling up to 6 leaf stage), infinity (seedling up to 6 leaf stage),

•    Crops commonly infected:
Wheat, grape, row crops, vegetable crops.

Optimal growing conditions:
Soils that are nutrient rich and moist with high sunlight exposure. It is a common weed of reduced tillage and is found growing on most soil types.



Chemical Control

Products that control


Region:  Other

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