More ideas from Ирина
Use Broken Plates for Ground Cover  You can use them in place of mulch to give certain areas a bit of color. Instead of filling in around your trees with mulch or pebbles for instance, use those broken plates or terra cotta pots. You can do them in all one color to make it look really elegant or mix it up for a look that is more fun and exciting. It’s a lot cheaper than mulch and pea gravel and will give you a really unique look in your garden areas.

Maybe in a circle around the tree--leaving some space in the center for the trunk? Repurpose Broken Plates for Colorful Garden Ground Cover Check with an Arborist to see if this is good for the tree. I'd do this by the curb with a walkway light in it.