Chenopodium album
Fathen (Chenopodium album), pronounced fat-hen and sometimes called fat hen, is one of the most serious weeds of cropping throughout New Zealand. It is an annual that germinates in the spring and early summer and then dies off in the autumn with frosts. Fathen is an extremely vigorous weed that can quickly outcompete and smother crops. An upright plant that can grow to 2 m tall and is a prolific seeder.

Fathen (Chenopodium album) is a spring germinating annual weed that is regarded as one of the most pernicious weeds in New Zealand. Very common and capable of growing up to 2 metres tall, fathen is a seriously competitive weed in all cultivated crops. Fathen is regarded as the most competitive weed in beet crops globally.


  • Long, slender, oblong shape
  • Apex rounded and stalked


  • Oval to egg shaped
  • Sugar-like crystals on new leaves

As plants mature they have an upright erect growth. Can grow up to 2 metres tall but in adverse conditions can flower as plants less than 10 cms high.

Leaves are grey-green, of variable shapes, coarsely toothed with stalks. Multiple seeds are produced prolifically on stems.

A mature plant can produce up to 20,000 seeds. Susceptible to frost so only grows through the spring and summer.


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