Common Lambsquarters - Weed of the Week

A Weed with Uses Dating to the 9th Century

Common lambsquarters ( Chenopodium album) is a weed that belongs to the pigweed (Amaranthaceae) family under the goosefoot (Chenopodiaceae) sub-family with leaves that resemble the shape of a goose’s foot. Its etymology may be traced back to the 9th century English harvest festival called “Lammas quarter.” Then, during the consecration of a loaf of bread made from the first harvest of grains carried out to mark off that quarter, a lamb was brought to the altar with meals partially characterized by greens made from this plant, which is how it came to be known as common lambsquarters.

Common Lambsquarters Identification

Common lambsquarters is a summer annual considered to be a major weed in North American row crops, such as corn and soybean, as well as sugar beet and potato. This relatively shallow-rooted herbaceous plant grows under a wide range of conditions, especially in disturbed and fertile habitats, such as barnyards and farmsteads. The stems have reddish streaks on them and are somewhat succulent. The leaves, also succulent, are powdered especially on the undersides with a mealy substance, giving it a whitish, lustrous appearance. Being in the same sub-family as spinach and beets, it may harbor pests and diseases of these crops, such as beet leafhoppers and spinach mildew. It also may serve as an alternate host of the insect common stalk borer, a pest of tomatoes and corn, and the green peach aphid (see photo below). It is a prolific seed producer with each plant producing over 70,000 seeds that possess a dormancy of over 20 years.

As alluded to earlier, common lambsquarters is considered to be a leafy vegetable. Seedlings, leaves or tender stems can be consumed fresh or boiled as a potherb. It is considered to have higher levels of proteins, vitamins and minerals, such as iron, than cultivated spinach or cabbage. Seeds can be dried and ground to prepare bread, cakes or gruel – the food grain quinoa belongs to same genus as common lambsquarters. An oil called ascaridole, possessing anthelmintic properties, can be extracted from the leaves of common lambsquarters. While this plant is considered to be of value as a fodder, large quantities may lead to nitrate poisoning in livestock and oxalic acid poisoning in sheep and swine.  It is also known to take up significant quantities of phosphate from the soil during early stages of growth.

Controls for Common Lambsquarters

During the early stages of its life cycle, common lambsquarters can be managed by mechanical methods, such as hoeing or cultivation, to control small populations. Mulches, such as black plastic or straw over newspaper, are effective to control this weed in backyard gardens.

Large populations may be controlled by application of herbicides specific to labelled crops. Commonly used selective herbicides containing the active ingredient dicamba effectively control this weed, especially during early stages of growth. Common lambsquarters biotypes have developed resistance to herbicides in the triazine and ALS-inhibitor families of herbicides in North America.