Common Chickweed

Biology

Common chickweed is a winter annual broadleaf weed. It forms dense, prostrate patches in turfgrass throughout North America. It can grow much taller when it’s not mowed. This winter annual germinates from seed in late summer or early fall. However, germination timings can vary throughout the year. Its prostrate growth habit and capabilities to withstand low mowing practices make common it a widely distributed turfgrass weed in all regions of the United States.

Identification

It is predominantly a winter annual broadleaf weed. It can be identified by its prostrate growth habit and leaf shape. The leaves are located opposite each other. The stems may be hairy on older portions and smooth on newer growth. Additionally, leaves are light green. They are smooth, and oval- to egg-shaped that come to a point at the apex. Leaves located on the upper portions of the stems have no petioles (leaf stems) while leaves located lower on the stems have long, sparsely-hairy petioles. It produces small clusters of white flowers with five daisy-like petals in early spring. Flower petals have a deep centered lobe that makes it appear as though there are ten petals.

Cultural control

Proper turf maintenance such as adequate mowing height, fertilization, and irrigation will help to develop a dense, aggressive turf capable of out-competing invading weeds. It’s also an indicator weed. Meaning its presence might indicate underlying management issues. For example, it thrives in compacted soils that are consistently moist or poorly drained. Its presence might indicate that the soil should be cultivated. Additionally irrigation practices should be adjusted to reduce excess moisture in the soil. Common chickweed also thrives in shady conditions. thus, efforts to reduce shade if possible, such as pruning tree branches, may also help turf out compete common chickweed. Hand-pulling common chickweed when populations are small may also be an effective cultural weed management tool.

Biological control

None known for specific use in common 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 common chickweed; however, their ability to control common chickweed has not been effectively researched.

Chemical control

Control options include both pre- and postemergence management strategies. Preemergence herbicides such as Gallery 75 (isoxaben), Pendulum (pendimethalin), Barricade (prodiamine), and Dimension (dithiopyr) are available for use in home lawns; however, it is important that they are applied prior to common chickweed germination in autumn.

Postemergence control can be achieved with repeat applications of two or three-way mixtures of 2,4-D, dicamba, MCPP, or MCPA in cool-season turf. In warm-season grasses, Manor (metsulfuron), Katana (flazasulfuron), or Celsius (thiencarbazone + iodosuluforn + dicamba) can control common chickweed when applied in combination with a non-ionic surfactant (0.25% v/v).

Most of these herbicides require supplemental applications for adequate control especially in spring when common chickweed plants are larger.