Identification and Reproduction

Identification: 

• Purple deadnettle is an annual or a biennial plant in the Lamiaceae (mint) family.
• It has square stems, fibrous roots, and typically do not exceed 30 cm. 
• Leaves are opposite, oval-shaped, purple to lavender, and crowd near the top of the stem.
• The flowers are pink or reddish-purple with a whorl-like arrangement. 

Reproduction: 

• The flowers are self-pollinating and usually bloom in the spring.
• The plant can re-grow from fragments of the roots or stem.

Habitat & Ecology

• This plant favours exposed open environments. 
• Often found in meadows, forest edges, roadsides and gardens. 

Impacts

Ecological: 

• Like many species in the mint family, purple deadnettle is an aggressive grower. 
• Rapidly covers any available growing space and will steal nutrients and water from other vegetation. 

Management

Mechanical/Manual Control:

• Small infestations can easily be removed by hand pulling. Removed plants should be bagged and disposed of. 
• Cutting plants prior to flowering will prevent further spread. 
• Do not leave any plant fragments on site as these will re-establish. 
• Sheet mulching is also effective - instructions can be found here.

Resources

Download the Garry Oak Ecosystem Recovery Team's Factsheet on Purple Dead-nettle here. 

View header photo here.