Roundup; but it only works during growth so it might be too late.. It
wont work in spring- til saps go both up and down. Test first

And it would be wise to make sure seed germinated - I wish they made
something that killed seed. Most are 'controls' ie: prevent it from
germinating for maybe 3 months, then it germinates.

There are two companion products - Team for grasses and Gentry for weeds
that let plants germinate, then kills them. But I cant find them.