This is something that newbies or beginners struggle with and can lead to damaging your lawn by adding to strong a product to it. Rule 101 is very important for people new to lawn care.
You should do this before buying or applying any products like fertiliser or weed killer to your lawn or yard
Did you miss our previous article...
https://lawnmaintenancetips.com/lawn-care-schedule/when-to-fertilize-a-spring-lawn-best-time-to-apply