The plant in the photo is prostrate knotweed. Go here to learn about it:
Can I just ariator it, or do I have to re sod? We just did a re sod 5 years again, and it's very spendy. Do I place grass seed when I pull plugs?
You don't have to re-sod. Aeration as recommended will improve growing conditions for the grass and discourage knotweed. However, it may take two or more years to achieve full control. Pre-emergent and post-emergent herbicides can be used to speed the process.