Pavers and other landscape masonry are available in many styles, sizes and colours for you to build patios, walkways and other hardscape outside your home. Building a tree ring is a simple way to protect the tree's base from the lawnmower and string trimmer while providing additional space for you to grow flowers. As you plan your tree ring, do remember that you should leave the base of the tree exposed. If it's a young tree, allow room for the trunk to thicken as the tree grows.
Lay a garden hose or rope in a circle around the tree where you plan to build the outside diameter of the tree ring. Measure the length of each paver. Adjust the diameter of the circle so you don't have to cut the landscape masonry to fit. Sprinkle flour over the hose to mark the outer diameter, then remove the hose.
Use a spade to dig a trench the width of your pavers around the tree. Use the flour circle as your guide. Dig the trench 10 to 15 cm (4 to 6 inches) deep.
Fill the trench with 5 cm (2 inches) of small gravel. Use a hand-held plate compactor to tamp the gravel firmly into position. Add 5 cm (2 inches) more of gravel and compact it. Fill the trench with gravel until it's level with grade. Compact it.
Set the first row, or course, of pavers on top of the compacted gravel. You may need to make slight alterations in how you set the pavers to get them to fit in the circle. Use a level to ensure that the first row sits evenly.
Place the second course of pavers on top of the first. Stagger joints so no two joints line up. This makes the tree ring more structurally sound. Bind the two courses together with construction adhesive applied with a caulking gun. Continue setting pavers in place until you reach the desired height.
Top the tree ring with a row of wider pavers to create a capstone. If you prefer, you may omit the top row.
Select pavers designed for use in a circle to avoid cutting individual stones. Score stones with a chisel to cut them. Tap with a hammer to break off the excess material. Allow space around the base of the tree trunk as you fill the tree ring with a shallow layer of mulch or potting soil. If you plant flowers or shrubs in the tree ring, allow extra water for them as well as the tree.
Piling soil over the roots of trees can damage even mature trees, according to online resource Trees Are Good.