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Corn Speedwell

Best Management Practices:

Corn Speedwell

Corn speedwell is a low growing, cool season, annual broadleaf weed that has oval or egg-shaped leaves with toothed margins and prominent veins. The leaves and stems will have fine hairs on them and the flowers of corn speedwell are light blue.  It is considered a winter annual that usually germinates in the fall season and into winter.

Pre-emergent herbicides work by killing germinating seeds from weedy plants like corn speedwell.  Normally, an application of a pre-emergent in mid-September will work well. 

There are several pre-emergent herbicides that can be used to control corn speedwell in most turfgrass sites including bermudagrass, St. Augustinegrass, zoysiagrass, and buffalograss.  Examples include:  XL- 2G (Benefin plus Oryzalin), Pendulum 2G or Anderson 11-3-11 (Pendimethalin)  and Balan 2.5 G (Benefin).

These herbicides can be effective if used when the corn speedwell is very young/immature and actively growing. Examples of effective post-emergent herbicides include:  Trimec Southern2-4-D Amine #4, Weed Free Zone or Speedzone.  They work very well if used in the correct manner and in accordance with the product label.  It may require multiple applications to obtain excellent control with these post-emergent products.  CAUTION:  Make sure you read the labels carefully for the tolerance level of your specific turfgrass for all herbicides.

Best Management Practices courtesy of:

Bes-Tex Supply, LLC P.O. Box 664 San Angelo, Texas 76902 Ph. 325-653-1300