>I have mulch blades and I bag it.
>
>Keep it pretty low.
>
>I’m about to get a lawn service tho. I need help growing
>grass in the back yard. I’ve tried to grow for a few years
>and nothing. Prolly need soil or have them lay down some
>grass.
>
>

Never cut it low. Keep it at around 3-3.5” for the hot summer months ahead.

Sounds like you need to kill all of your grass in the back and start over. Get some good manure and seeds and you should be good hopefully.