Arizona has a wide range of planting zones, leading to an equally wide range of flowering plants. The zones in Arizona do not run north and south as they do in most states. In Arizona, they are determined by the low-lying deserts and the various elevations in the mountains. Flowering plants in Arizona come in all sizes and shapes, in a variety of colors and are adaptable to different growing conditions.
Desert willow (Chilopsis linearis) is a multi-stemmed deciduous tree that can grow to 30 feet tall. The tree produces leaves that grow from 1/2 to 3 inches long and 1/2 to 1/4 inch wide on branches that droop like those of a weeping willow tree. The white, burgundy or pink bell or funnel shaped flowers grow in clusters at the end of the branches and bloom in May and June. Long seed pods, measuring 4 to 9 inches, appear when the flowers are done and stay through the winter. Desert willow is a native of the Southwest and in Arizona, it is hardy in zones seven through ten, where the average low winter temperature does not go below 0 degrees F. The tree likes full sun the best, but can take a light shade situation. It does best in a sandy soil, but can handle rocky soil as long as it is allowed to go dry between waterings, which should be infrequent, but long-lasting.
American plum (Prunus americana) is also known as the wild plum. The plant grows from 20 to 40 feet tall and produces deciduous leaves that are 3 to 4 inches long and fragrant 1-inch-wide white flowers that bloom at the same time the leaves appear. Yellow-brown to red-purple fruit about an inch in diameter replaces the flowers. In Arizona, the plant is hardy in zones five through eight, where the average nighttime winter temperatures get no lower than minus 20 degrees F and no higher than 20 degrees F. It does best in full sun, but can take dappled shade. It is able to live through a drought once it is established.
Hopseed bush (Dodonaea viscosa) is an evergreen shrub that grows from 12 to 15 feet high and about the same in width. The plant produces narrow dark green leaves and green-white flowers that grow in clusters and bloom in the early spring. The fruit is a three-sided pod that starts out green and becomes tan as it ages. In Arizona, it is hardy in zones eight, nine and ten and up, where the winter temperatures get no lower than 15 degrees F. It prefers full sun, but does OK in partial shade. Hopseed bush does well in any type of soil, as long as it is well-drained.