Gazania (Gazania rigens) produces brilliant daisy-like flowers, stays low and doesn't spread beyond 1 foot in diameter, which makes this perennial great for borders. Because it performs well when exposed to full or part sun or filtered shade, it is a great choice for a ground cover beneath trees with relatively dense canopies. However, this plant species succumbs to root diseases when soils are not well drained or are overirrigated. It may decline during hot weather.
Trailing lantana (Lantana montevidensis) is a good choice for areas where a fast-growing, sprawling low plant with showy flowers is desired. This plant produces many lavender flowers throughout the year, provided there is plenty of water and relatively warm weather. It tolerates marginal soils and can perform well in full, part or reflected sun. The disadvantages of trailing lantana are that it can be invasive and will be unattractive at cooler temperatures.
Prostrate myoporum (Myoporum parvifolium) produces bright green foliage and white star-shaped flowers. It is fast-growing and can reach 9 feet in diameter but will only reach 3 inches in height. It will do well in full sun or part shade and requires frequent deep irrigations during hot weather. It can be difficult to establish.
Dwarf rosemary (Rosemarinus officinalis prostratus) is a durable, low-growing plant that has dark gray-green, needle-like foliage with small light blue flowers in winter and spring. This relatively slow growing plant will spread to a width of 4 feet and grow to about 2 feet tall. It does well with full or part sun and can tolerate poor shallow soils but requires good drainage. The negatives of this plant are that it can be difficult to establish, can succumb to root rot in poorly drained areas and will attract bees during bloom.
Periwinkle (Vinca major) is a fast growing, lush, green ground cover that performs best where there is afternoon shade and plenty of water. In spring, it will produce single blue 2-inch diameter flowers. This plant can grow to about 5 feet wide by 1½ feet tall. It can take over an area if not trimmed frequently and will compete with other plants for water. Periwinkle may sunburn in the summer but recovers quickly when conditions cool. In addition, it can die back suddenly.
Sprenger asparagus (Asparagus densiflorus ‘Sprengeri') produces ferny, light green foliage that is attractive when used for low borders or edgings as a ground cover. This light-colored, soft-textured growth provides a striking contrast to dark evergreens or colorful flowers. Sprenger asparagus mounds to a height of 1 to 2 feet and can grow to 5 feet in diameter. It tolerates poor soils and can grow with any amount of light, but becomes unattractive in deep shade. Under hot dry conditions, stems and foliage may die back or plants may yellow.
Australian saltbush (Atriplex semibacata) is a good ground cover for open areas in desert or wild gardens where there will be little or no maintenance. It has gray leaves and will grow to about 1 foot tall and 6 feet in diameter. It is well adapted to saline alkaline soils, grows quickly and can survive on little water under low desert conditions; however, its appearance may be too wild and rustic for front yards or formal settings.
Creeping and blue carpet juniper (Juniperus horizontalis) are both relatively slow-growing ground covers that are good choices for large sunny areas with afternoon shade. Both varieties may expand to about 8 feet in diameter. Creeping juniper is bright green and will be about 1 foot tall at maturity. Blue carpet juniper is silver blue and will reach a height of 4 inches. Junipers are sensitive to very light rates of nitrogen fertilizer and can be damaged by heavy applications. Reflected heat may burn junipers when planted near south-facing walls or pavement, but overall, these are durable plants.
Many of these perennials are available at home garden stores and early fall is a good time to plant. While shopping for plants, avoid spindly yellow plants. In general, healthy plants will have green compact growth.