Starting from the ground up
So now that both of my parents have retired, I wanted to give them something that they can do everyday to keep them busy. So I thought of cleaning up this land space in front of our house where there used to be a garden. For years this 30 sqm. patch of land was left unattended, uncleaned and the soil left to dry, so the other week I pulled out the weeds and loosened the hardened/compacted soil. I also placed coffee grounds which I got from the local coffee shops to somehow add organic material, so now my question is, before I place newly purchased topsoil and frog grass on this small patch of land can I spray it with organic weed killer mix? (Vinegar, Salt, Dishwashing Liquid) I read that if I don't want anything growing from any land that I should use this, but what if my intention was just to make sure that the weeds don't come back from the old soil and not harm the new soil? I'm not sure if this makes any sense but I'm hoping someone might understand me. Thank you in advance.