How can I make DIY weed killer?

Try this: https://www.craftylittlegnome.com/permanently-kill-grass-weeds/

1 gallon of vinegar, 1 cup of salt and 1 tablespoon of Dawn

This article on Natural Weedkillers is really helpful

https://www.hometalk.com/diy/outdoor/pest-repeller/the-truth-about-natural-weed-killer-exposed-33053043

There are several here on HT:

https://www.hometalk.com/search/posts?filter=weed%20killer

I just soak the area and pull the next day...I need the exercise!

This is not an exact science – approximate measures are totally fine 1 gallon white vinegar and cup Epsom salts and ¼ cup liquid dish soap Combine ingredients in spray bottle and treat weeds at the hottest time of day for best results.

Selective herbicides ( wont harm grass) can be purchased at most retail venues —if you do not wish to use commercial chemicals preparations -there are diy homemade alternatives.

Recipes using natural household products can be a way to eliminate your weeds, these very helpful links from Hometalk are a great a great synopsis.

https://www.hometalk.com/diy/outdoor/pest-repeller/diy-weed-killer-38537988?

https://www.hometalk.com/diy/outdoor/pest-repeller/s-9-natural-weed-killers-that-will-save-your-summer-garden-17001086?

https://www.hometalk.com/diy/outdoor/pest-repeller/natural-weed-killer-20665086?

2 cups white vinegar

¼ cup salt

Squirt of dawn

Mix in a spray bottle. If you have a larger area, you can mix in a garden sprayer with larger quantities. Use when it will not be raining for a few hours so that it isn’t washed away.