I couldn't find a perfect place to post this question.

I have 4 yoshino cherries in a row that run parallel with the side street next to my back yard.

They are getting big enough to produce shade (6 or 7 years old) and so my bermudagrass isn't creeping in under them as it used to, and that is great. There are weeds under there though and I want to kill them all off and redo a layer of mulch to make the area a clearer border that is not part of the lawn. I was going to use round up on the weeds, but I've gone organic and am looking for another option. Would layering it with cardboard (I have plenty from my home recycling) and then some compost on top of that be a good solution?

By the way a groundcover could be in the future, but it is not reasonable this year with our water bans in Georgia.

Thanks Kevin