Hello

Sounds like you have either wild onion or wild garlic growing. Both of these weeds are controlled in the same manner. First, do not let them flower and set seed, as they can spread more that way.

Here are a couple discussions on how to control them. As always, read and follow all directions and precautions on any chemicals you use.

https://turf.purdue.edu/controlling-wild-onion-or-wild-garlic/

https://lee.ces.ncsu.edu/2015/02/wild-onionwild-garlic-kill-control-prevent-it-2/