I'm thinking that you're talking about mulching your containers. This is a topic that is brought up fairly often in this forum. If you click on the attached link, I've done the 'search' for you. You'll be able to spend some time reading what others do.

Personally, I don't mulch the top of my containers with anything.

Here is a link that might be useful: Click here

Al's mix, at least the way I'm making it, is almost like a mulch on it's own.

When I've used less chunky mixes, I've used all sorts of different mulches. The most common are fairly fine wood chips in shrub and grass pots, and chicken grit in succulent pots.

I add compost to the top of the container soil, on a irregular schedule. Seems to help feed the plants as well as help in weed suppression. Al