Xeriscape is not (necessarily) gravel and cactus. It is A sustainable landscape that conserves water and uses sound horticultural practices. In practice this means using plants appropriate for a give space, so hot loving plants in the hot dry areas, shade loving plants in the moister shady areas, grouping plants with similar water needs. The use of an appropriate mulch is a key part of xeriscaping. We use two basic styles of mulching:

Typically this is an aggregate or crushed stone placed over a good quality landscape fabric (if you can poke your finger through it or tear it, it isn't good quality). Sometimes this is called weed barrier, but it is the mulch that does most of the weed suppression, not the fabric. The primary purpose of the fabric is to prevent the aggregate from blending with the soil below but at the same time allowing water and air movement.

Typically in the Calgary market this is some form of wood product. A product of the lumber industry it is composed of bark and possibly chipped wood depending on the type of mulch. No fabric is used beneath it, as the organic material breaks down over time it becomes soil and more mulch is added to refresh. How often this is necessary depends on the environment and the type of mulch.