Certified GKH Gardening Expert
This article will help you with that: https://www.gardeningknowhow.com/problems/weeds/how-to-kill-chickweed-best-way-to-kill-chickweed.htm
Chickweed. Nasty. Must be removed before seeding - and this monster is very quick at seeding! If you are not fussy, and depending on where the infestation is, weed-killer is a solution provided welcome plants are not affected. However, my solution is called getting on your hands and knees and picking the plants out - roots can sometimes be deceptively deep. And you need the root out as if left, it usually raises up again. Someone once suggested soapy water, but for me this only does for washing hands - and sometimes feet! Cheers from Squadronleader.