Use rocks of one geological type. Good drainage is necessary. Plant a variety of species in the rockery. The Garden should not be larger than can be easily maintained. Use rocks of one geological type.
Rocks are available from nurseries, landscape contractors and rock dealers.
An effective rock Garden should have several large rocks, some weighing 200 pounds or more. Set the rock into the ground so at least one-third is buried. Place rocks in a natural way, following the grain of the rock. Position rocks to control soil erosion between rocks and to allow soil pockets of various sizes for plants. Use smaller, similar rock as a mulch.