Can Vascular Plants Live in Dry Environments?

Trees

• Trees, the tallest vascular plants, provide shade, a valuable commodity in the desert landscape. The blue leaf wattle (Acacia saligna) grows well in full sun and well-drained soil. It requires monthly irrigation once established and tolerates heat. This semi-evergreen has long, linear foliage, dark wood and produces showy panicles of yellow spring blossoms. Blue leaf wattles are native to Australia and grow to 25 feet tall with a 20-foot spread. The weeping bottlebrush (Callistemon viminalis) grows quickly from 20 to 30 feet tall with a slightly narrower spread. This evergreen has linear, furry leaves that turn reddish-green with maturity. It blooms with spiky red flowers in spring to summer and prefers full sun to partial shade and weekly watering.

Shrubs

• Some shrubs can live off of natural rainfall, but most require some irrigation during the summer months. The century plant (Agave Americana) grows to 7 feet tall and spreads to 12 feet wide. This native shrub has succulent, blue-gray foliage that resembles large, pointed swords. Leaves have serrated margins and pointed tips. Century plants produce flowers atop tall stalks. They thrive in full sun and tolerate drought, heat and partial shade. They survive on rainfall, but grow best with once-per-month irrigation in the summer. The triangle-leaf bursage (Ambrosia deltoidea) grows to 3 feet tall with an equal spread. This small, evergreen shrub has hairy, triangular, gray-green foliage and spiky branches. It prefers full sun and does not require irrigation once established.

Ground Covers and Vines

• Ground covers grow low to the soil and spread into a mat. The butterfly mist (Ageratum corymbosum) thrives in dry environments. This perennial grows to 12 inches tall and spreads to 3 feet wide. It has deciduous, heart-shaped foliage and blooms with clusters of light blue and purple flowers in summer. Butterfly mist prefers full sun to partial shade and requires biweekly watering in the summer. Vines can created shaded areas or grow on prostrate as ground covers. The queen's wreath (Antigonon leptopus) grows to 30 to 40 feet tall and blooms with red, pink and white, long-lasting blossoms in spring. This vine is deciduous in cooler climates and perennial in warmer regions. It prefers full sun and tolerates heat, drought and a range of dry soils. It thrives with weekly waterings in the summer.

Perennials and Annuals

• Perennials live for at least three years. Sundrops (Calylophus hartwegii), a woody perennial, grow in clumps to 1 1/2 feet tall. They bloom with cup-shaped yellow flowers that only last one day. Sundrops have narrow, evergreen foliage and are native to the southwestern U.S. They thrive in full sun to partial shade and tolerate reflected heat. These drought-resistant flowers require biweekly irrigation. Annuals live for a single growing season. The African daisy (Dimorphotheca aurantiaca) grows from 12 to 18 inches tall and blooms with yellow, orange and white flowers starting in early spring. This South African native prefers full sun, well-drained soil and weekly irrigation.