1. Put pavers together without adhesive to make sure the size and shape are what you want.
2. Use landscape block adhesive to attach pavers. Run a thin bead of adhesive along the edges, press pavers together, then let sit for 24 hours. Clamps shouldn't be needed.
3. Glue the bottom piece on using the same method as for the sides. However, leave a few gaps between the adhesive beads so excess water can drain.
4. Wait until glue dries completely, then add your favorite plants and enjoy!