Clay pebbles: yay or nay? I added soil topper to most of the plants I repotted this year (either gravel or mulch). It definitely causes water retention, which throws off the Planta watering schedule. But Amazon threw some pretty multicolor clay pebbles on my homepage, and I thought theyād be neat for succulents. Have you used them as a topper or a substrate, and if so, do you recommend them?