River rock is a versatile hardscape material that is used as an accent feature and for erosion control on sloped properties. Curving through a desert yard, river rock can appear to be--with a little imagination---a running stream. Planting greenery along the edges of the imaginary stream bed such as the velvet-leaf senna with its bright yellow clusters of flowers or the asparagus fern with its bright green feathery stems further adds to the illusion of a desert oasis.
The lantana plant and its relative trailing lantana are low maintenance plants that come in an array of vibrant colors. Mixing the colors across a landscape border can create a dazzling display that remains in bloom most of the year. Lantana colors include yellow, pink, red, orange, lavender and white. The plant does not create leaf litter, but the stems may become woody and need to be trimmed back annually.
Cactus and succulents come in many shapes, forms, sizes and textures. Plant them in several groups to draw attention to the plants' interesting contrasts. Spread rock mulches of slightly different desert earth tones around these clusters and you create small islands of desert beauty and mystery. The vertical growing saguaro, the red-flowered prickly pear and the squid agave with its spreading tentacle-like stems make an interesting grouping--but the choices and combinations are almost endless.
Group two large boulders with several smaller ones to make an eye catching display. Make sure the type of rock matches, so it looks like a naturally weathered part of the Sonoran desert. Putting plants around the boulder grouping such as the flame honeysuckle with its orange-red flowers, the turpentine bush with its yellow blossoms or the more delicate pink fairy duster creates an interesting contrast between the hard stone and the soft. colorful plant forms.
Rock mulches are often used to cover bare areas or act as transitional features between one part of the yard and another. A more colorful choice would be to carpet the area with moss verbena, a low growing, evergreen perennial plant. Verbena can bloom from the end of winter to the onset of fall in warm regions. Flower shades are blue and violet. Frost can damage this plant, requiring it to be trimmed back in anticipation of spring re-growth.