Dodonaea is a plant genus that is part of the Sapindaceae family. It contains about 65 species of shrubs and small trees, most of which are native to Australia. The plants feature colored seedpods and flowers without petals. Landscapers usually plant these shrubs along walls or trellises and in containers. Most species in this genus are damaged by spider mites.
This genus was named after Rembert Dodoens, a 16th century botanist. Commonly, the plants in this genus are referred to as hop bush because they were historically used to produce beer. Most of the species have a variation of the common name. Dodonaea viscosa is called hopseed bush, and a variety of D. viscosa is called purple hop bush.
The majority of the plants classified as Dodonaea are native to Australia. Dodonaea aptera populates Western Australia, while Dodonaea petiolaris is located in each state of Australia except Victoria. Dodonaea angustifolia is a species that is found in several areas, including Australia, New Zealand, and South Africa.
Generally, the shrubs in this genus grow 13 feet (4 m) in height and spread about 8 feet (2.5 m). The spreading structure consists of lance-shaped leaves that are initially greenish yellow, but become tinged with purple as the fall approaches. The stems are multi-branched and dotted with small flowers.
The flowers do not have petals and range in color from pale yellow to red. They typically bloom from August to October. All the flowers on one plant are either male or female, thus they can not self-fertilize. The plant either produces microspores or megaspores, which are the male and female spores, respectively.
A characteristic feature of this genus is the colorful seedpod. The seedpods are initially green, but become greenish yellow, pink, and red before drying to a brown color. The fruit is usually three-sided.
When growing Dodonaea species, it is recommended to plant them in an area that is free of frost and exposed to direct sunlight. The soil should be well-draining and fertile. A variety of soil types can be used including loamy, sandy, and clay. The pH of the soil can be acidic or alkaline.
Insects such as the red spider mite feed on the plant tissue. Red spider mites are fast moving, tiny red spiders that suck the sap out of the leaves. They cause a dusty appearance on the underside of leaves. If webbing is present, then the infestation is large. Applying an insecticidal soap to the shrub eliminates most of the infestation.