P&PDL Picture of the Week for
February 1, 2010

Chickweed: A Winter Foe

Glenn Nice, Weed Diagnostician, Department of Botany & Plant Pathology, Purdue University

Common chickweed (Stellaria media (L.) Vill.) is rated as one of Indiana top ten winter annuals.  This winter annual can be found forming dense mates of vegetation in agronomic fields or coming up in cracks in the sidewalk.  Common chickweed will germinate in the fall, over winter and flower in spring to late summer.  It has opposite leaves that are either egg-shaped or shaped like a football.  The flower is about 0.1 to 0.2 inches wide with 5 white petals.  At first look it might look like it has 10 petals, but as like many of the plants in the pink family, the petals have notches.  In the case of common chickweed the notches are deep enough to appear like 10 petals instead of 5. 

Common chickweed can be controlled with glyphosate when applied in the fall, but control becomes more difficult when used as a spring burndown.  The use of 2,4-D alone in the fall or spring will not adequately control common chickweed and adding it in the spring to glyphosate does not show a benefit. 

Before soybean, tank mixes that contain Express or pre-mixes that have its active ingredient, tribenuron methyl, such as Canopy EX or Cloak EX have great activity on common chickweed.  These products can be applied in the fall or in the spring.  Metribuzin + Gramoxone Inteon + 2,4-D can burndown common chickweed but have to be applied at least 7 days before planting soybean when using 0.5 lb ai 2,4-D and 30 days before planting soybean if using more than 0.5 lb ai/A.  Valor XLT or Envive + glyphosate will also provide excellent control.

In corn, simazine + 2,4-D or Autumn + glyphosate in the fall control common chickweed.  In the spring tank mixes of Balance Flexx or Corvus + atrazine and either 2,4-D or glyphosate will provide excellent burndown of common chickweed.  Lumax, Lexar or atrazine + Hornet WDG will provide excellent control.  The link below provides ratings of control with several treatments from the 2010 Weed Control Guide for Ohio and Indiana [http://www.btny.purdue.edu/Pubs/WS/WS-16/BurndownTable.pdf].

Click image to enlarge

Purdue Plant & Pest Diagnostic Lab Purdue Cooperative Extension Service