Chickweed (Stellaria media) is a weed with small white flowers that is common in the home lawn and garden. In a new lawn, chickweed uses up the water and nutrients that the grass needs in order to grow well and become established. Also, chickweed will fill in the bare spots, rather than the grass, so getting rid of chickweed in a new lawn is essential if you want a full, lush and green lawn in the years to come.
Pull chickweed up manually when the soil is slightly wet. Discard it in the trash rather than the compost pile to prevent it from growing back in other areas of your landscape. If you inadvertently pull up your new grass (which has weak roots) while pulling up chickweed, stop and proceed to the next step.
Spray chickweed directly with an herbicide that is effective on chickweed and safe for grass, including new grass. For example, herbicides that contain 2,4-D or dicamba work well. Adhere to the instructions on the label and reapply as necessary.
Apply a pre-emergent herbicide in the early spring to prevent growth of any seeds that may have survived the previous year's treatments. For example, an herbicide that contains pendimethalin or DCPA will help prevent chickweed in lawns.