Integrated Pest Management
Purple Deadnettle
Lamium purpureum
Description
- produces square-shaped stems that grow 4 – 16 inches tall; stems are branched at the base and purplish in color
- leaves are hairy, arrow shaped and oppositely arranged on stems; leaves have prominent veins that are recessed on blades and leaf margins are toothed
- leaves are clustered around stem tips and the uppermost leaves are smaller and reddish purple in color, giving the plant the appearance of vertically standing hooded figures
- flowers are small, purple and circle upper leaf axils; if studied carefully, flowers resemble tiny orchid blooms with a white face and purple spots
Location
- commonly grows in planting beds and lawn areas
Life Cycle
- a winter annual with seeds that germinate in the fall although a lesser portion of seeds may also germinate in the spring
- seedlings do not germinate during hot summer temperatures; purple deadnettle plants complete their life cycle before hot temperatures set in and seeds can germinate immediately as long as temperatures are not too high
IPM Recommendations
- Hand-pull plants in planting beds prior to seed maturation.
- Apply an appropriate pre-emergent herbicide prior to seed germination or apply an appropriate post-emergent herbicide directly to target weeds.