A 2" deep layer of plain un-colored cedar mulch will help with weeds, some kinds of bugs, mice and retain moisture for them to boot.
If you have slugs around, just pick up a copper scrubby at the grocery and pull the strands apart. I cut myself doing this... that shit is sharp haha.
You spread a half dozen strands around the bases of each plant and the slugs and snails won't cross it. Apparently it's like tasting a penny, only to them it's times a thousand so they just go away.