Even if you could lay a perfect ring of bark mulch around your tree, it would soon look ragged and need replenishing. These tree rings look just like bark mulch, but they're actually thick mats of recycled tire rubber that will stay in place year after year – you can even mow right over them! They suppress grass and tough weeds, so you won't damage trees by trimming too close, but they let in air, water, and nutrients. Earth-friendly, 100% recycled rubber Suppresses weeds more effectively than bark mulch Thick, durable rubber mulch won't scatter Available in four sizes to fit every tree, from saplings to mature specimens The 48" and 60" sizes cannot be shipped to AK, HI, PR or VI, and cannot be sent via faster shipping methods Approx. 1" thick 48" diameter is in two sections for easy placement 60" diameter comes in four sections Made of recycled tire rubber Gardener's Supply Exclusive