"Gold shower" is one of many common names for evergreen flowering shrubs from the genus Galphimia. Plants from this group may also be known as golden thryallis, shower of gold, or rain of gold. The gold shower shrub is native to Mexico and the southwestern United States, but it may be found growing worldwide in tropical areas. It is a popular decorative garden plant, largely due to the attractive, gold-colored flowers that give the plant its name.
The species most commonly referred to by the name "gold shower" are Galphimia gracilis and Galphimia glauca. Both species are native to Mexico. They are very similar in appearance, yet they can be easily differentiated by observing their petals. G. glauca maintains its bright yellow petals after fruits develop on the shrub, whereas G. gracilis gradually loses its petals as it grows fruit.
Gold shower shrubs typically achieve an average height between 4 and 6 feet (1 and 2 meters), and an average width between 3 and 4 feet (about 1 meter). The shrubs have smooth, shiny oval-shaped leaves that are grayish green in color. Their stems and branches are a reddish brown color and are covered in fine hairs. The numerous bright yellow flowers that give the shrub its name grow in clusters all over the plant and usually bloom between the summer and early fall months. However, when the plants are grown in truly tropical temperatures or in a greenhouse environment, their flowers may bloom year-round.
A gold shower shrub is usually propagated from seed or from branch cuttings, which are small pieces of branch that are removed from a parent plant and then planted and grown as separate plants. The branches used to propagate gold shower should be young, not still green and flexible but not yet hardened with age. Shrubs may also be purchased as seedlings from a plant nursery and transplanted in the garden.
Caring for gold shower shrubs is relatively easy. The plants prefer sunny conditions, although they may also be planted in partial shade. Shrubs planted in a shadier location may grow somewhat untidily and require more pruning. Even shrubs grown in full sun will require some pruning to remove old growths and unruly branches. The shrubs also prefer soil that is on the sandy side, and are resistant to drought conditions. Some species are also resistant to garden pests, such as rabbits and deer.