Hello Nick,

Thank you for the question.

This appears to be hairy bittercress. A member of the mustard family, it is a winter annual, meaning it germinates in the late summer and overwinters as a small, clustered rosette. In the spring, when the soil warms, it quickly blooms and sets seed. Lots of seeds. These spread a great distance from the parent plant and lay in wait to start a new cycle in the fall. https://www.canr.msu.edu/news/hairy_bittercress_a_weed_to_watch_out_for

No action can be taken now. The seeds have been spread. In the later summer (mid-August to mid-September), you can spread a pre-emergent herbicide (examples are contained in the following link) to limit the number of seeds that can germinate. In the spring, you can use spot treatments of post-emergent herbicides (examples also given in the following link) to kill the over-wintered rosettes hopefully before they bloom and set seed. You can also mow frequently in the spring to remove the stalks and the blooms before they are pollinated and form the seed heads you have now. https://extension.psu.edu/lawn-and-turfgrass-weeds-hairy-bittercress

Hope this helps.