Southwest-facing gardens can be difficult to landscape successfully, but it certainly can be done. The plants must be able to thrive in hot full sun exposure and harsh winds. A combination of flowering plants will provide color from spring to fall, but deciduous and evergreen shrubs can also be used in the garden. A variety of plant heights, textures and flowers results in a more diverse and interesting landscape.
Full-sun flowering perennials can be planted in a southwest garden for foliage and flowers year after year. Chrysanthemums (Chrysanthemum spp.) are perennials that are generally hardy in U.S. Department of Agriculture plant hardiness zones 5 to 9. They provide greenery and texture in the spring and summer. When the days begin to shorten at the end of the summer, they bloom, providing colorful flowers until the first hard frost. The plants grow to a height of 1 to 3 feet and bloom in a variety of colors including orange, pink, purple red and white. There are 13 different flower forms available from single to pompom, depending on the hybrid or cultivar. Verbena hybrids (Verbena x hybrida) bloom from spring to first frost in shades of pink, purple or white. Many verbena hybrids are hardy only in USDA zones 9 to 10, but some like “Annie” (Verbena “Annie”) are hardy in USDA zones 4 to 8.
Full-sun annuals are usually inexpensive and can be changed from year to year for a different look or flower color. Zinnias (Zinnia elegans) are annuals that bloom from spring to first frost in a wide variety of colors including orange, pink, purple, red, white and yellow. They range in height from 6 inches to 2 feet and may have small or large fancy flowers, depending on the cultivar or hybrid. Cockscombs or feather celosias (Celosia argentea) bloom from late spring to first frost, producing unusual flowers in brilliant shades of orange, pink, purple, red or yellow. The plants are 6 inches to 3 feet tall, depending on the variety or cultivar. They are perennials that are hardy in USDA zones 10 and 11, but they are grown as annuals everywhere else.
Full-sun deciduous flowering shrubs can be grown in a southwest-facing garden for flowers and bright fall foliage. “Tor” birchleaf spireas (Spiraea betulifolia “Tor”) grow to a height of 2 to 3 feet and produce clusters of white flowers in the spring. When temperatures cool in the fall, the foliage changes to various shades of orange, purple and red. They are hardy in USDA zones 4 to 8. Red Knock Out roses (Rosa “Radrazz”) are hardy in USDA zones 5 to 9 and have good resistance to foliage diseases that usually make growing roses difficult. There are also pink- and yellow-blooming Knock Out roses. They grow to a height of 3 to 5 feet and bloom from spring to first frost, although in warmer climates they may bloom year-round.
Full-sun evergreen shrubs can be planted in a southwest-facing garden for year-round greenery and texture. “Cuprea” (Thuja plicata “Cuprea”) and “Rogersii” (Thuja plicata “Rogersii”) are smaller western red cedar cultivars that grow to only 2 to 4 feet tall. They are hardy in USDA zones 5 to 9. Japanese shore or Blue Pacifica junipers (Juniperus conferta) are groundcover-type shrubs that grow to only 6 to 18 inches tall but 6 to 10 feet wide. They are hardy in USDA zones 5 to 10. Both of these needle-leaved evergreens can be grouped with birchleaf spireas and Knock Out roses.