LAMB'S QUARTERS

WHAT'S THAT WEED? SERIES

HOW TO IDENTIFY?   

• New growth and the underside of older leaves dusted with mealy white powder. 
• Leaves usually have WAVY or JAGGED edges and can be different shapes. 
• Flowers are small, green, and have no petals. 
• Stem is upright with MANY branches. 
• Plants are EASY to pull out. 

IS THIS ANNUAL PLANT A PROBLEM?

• YES. It’s an edible plant (cook it like spinach) that’s sometimes grown as an agricultural crop. 
• BUT it spreads QUICKLY, competes with other plants and uses a lot of water. 
• In some conditions it can accumulate HIGH LEVELS of nitrates, oxalates, or sulphates and become toxic to livestock.

HOW DOES IT GROW?

• Has short, branched taproots.
• Each plant has about 72,000 seeds! 
• Seeds can survive for 40 YEARS but will only grow if they are near the soil surface.
• Grows in DISTURBED soil in sunny places.
• Often found in vegetable gardens. 

HOW TO CONTROL? 

• It’s EASY to kill by weeding or hoeing. 
• Don’t let it go to seed. 
• Cover seeds with mulch and leave them buried – DON’T till the soil. 

Sources:
Colorado State University. Guide to Poisonous Plants. 

Royer, F. and Dickinson, R. Weeds of Canada and the Northern United States. 1999.

Weedinfo.ca: Lamb’s-quarters, Ontario Weed Committee, 2022.

Image:  https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons