Weed of the month for April 2014 is Mouse-ear Chickweed

Mouse-ear Chickweed  

Biology: Mouse-ear chickweed (Cerastium vulgatum) is a broadleaf weed that normally acts as a perennial; however, it has the ability to act as a winter annual depending climate conditions. Mouse-ear chickweed germinates by seed from late summer to fall or early spring. As long as cool climate conditions and moist soil persist, germination can also continue into the summer. Similar to common chickweed, its prostrate growth habit and capabilities to withstand low mowing practices make mouse-ear chickweed a prominent weed in turfgrass and other mowed areas throughout the United States.

Identification: Mouse-ear chickweed is a perennial broadleaf weed that invades turf through the spreading of prostrate stems which form dense, mat-like patches. In unmowed areas, plants can form a more upright mound which then give rise to spreading and invasive stems. Mouse-ear chickweed stems are sticky/hairy and are capable of producing roots when nodes (origin points for leaves) come into contact with soil. Leaves are located opposite of each other on the stem and are dark green in color, oval to oblong shaped, and distinctly hairy on the entire upper surface and along the veins on the lower surface. Leaves also lack petioles (stems) and tend to overlap like a cup around the main stem at the base of the leaf. From May to October, mouse-ear chickweed produces small white flowers with five petals that are deeply clefted to the point where it looks like there are ten petals. Each flower has hairy sepals (green leaf-like structures that enclose and protect unopened flowers) that are almost as long as the petals. Mouse-ear chickweed can sometimes be mistaken for common chickweed; however, common chickweed does not have hairy leaves and its nodes cannot form roots when they touch soil.  

Oblong leaves with dense hairs on upper surface

Oblong leaves with dense hairs on upper surface

Daisy-like petals with 5 petals. Deep clefts in the center of each petal give the appearance of 10 total petals.

Dense, mat-like growth at low mowing heights

Large patch of mouse-ear chickweed in cool-season turf

Cultural control: Mouse-ear chickweed can form dense, mat-like patches which help to crowd out desirable turfgrass. Cultural management practices to develop a dense, aggressive turf may help to hinder the invasive qualities of mouse-ear chickweed. Since it has a weak and shallow root system, the weed could be managed by hand pulling when populations are small enough and the expanding stems haven’t already rooted.

Biological control: None known for specific use in mouse-ear chickweed. There are some organic postemergence herbicides available for turf weed control such as pelorgonic acid (Scythe), acetic acid (5% or greater solutions), and medium-length fatty acids (Eugenol); however, these products do not differentiate between the target weed and the desired turf (non-selective). As a result, these products are often used as spot treatments for weed control in parking lots, along fence rows, and in other bare-ground areas.

Other organic products that contain iron HEDTA (FeHEDTA), may be used to manage mouse-ear chickweed; however, their ability to control this weed has not been effectively researched.

Chemical control: Control options for mouse-ear chickweed include both pre- and postemergence management strategies similar to those of common chickweed. However, since mouseear chickweed may behave as a perennial, a postemergence weed management strategy may be more effective.

Postemergence control can be achieved with repeat applications of two or three-way mixtures of 2,4-D, dicamba, MCPP, or MCPA. A repeat application may be required.

For more information on weed control, search this blog and check out our Turfgrass Weed Control for Professionals Publication.

For archives of past weed of the month postings, visit our Weed of the Month Archive.

Aaron Patton, Turfgrass Extension Specialist

Leslie Beck, Postdoctoral Research Associate