Common Name: Japanese Pittosporum
Scientific Name: Pittosporum tobira
Order: Rosales
Family: Pittosporaceae
Description Japanese pittosporum is an evergreen shrub that stands 8-15 feet tall with a 12-18 foot spread to for a dense and mounded form. This plant is easily recognizable with its cluster of extremely fragrant creamy white flowers that bloom to 2-3 inches in diameter during the late spring. The leaves are arranged into a whorled pattern with sessile leaves that are spatulate to obovate in shape and are 4 inches long with a prominent midvein.
Growth Habit Japanese pittosporum grows rapidly at first until it reaches 8-10 feet tall then growth begins to decrease, which is good considering it is mainly used as an ornamental shrug, therefore pruning can be maintained more easily. Other species of Japanese pittosporum have been developed that grow much slower and only reach heights as little as 2-3 feet at maturity.
Hardiness Zone(s) Japanese pittosporum is native to Japan and China but can grow in the USDA zones 8-10 and sunset zones 8-24. Japanese pittosporum grows well in both, full sun or shade exposure. This plant preforms and grows well in warmer climates than in cooler ones. When exposed to extreme cold the bark will split and often develop fungal infections.
Culture Japanese pittosporum grows well in a wide range of soil types as long as proper drainage of excess water is sufficient. It is very drought tolerant after it has matured and its initial period of rapid growth is over. Once it has reached adulthood the plant requires little water and maintenance. If grown in soils that are too wet Japanese pittosporum is very susceptible to root rot diseases and will rapidly die.
Diseases & Insects Japanese pittosporum is susceptible to several leaf spot diseases, many fungi galls, and root rot diseases. Leaf spot diseases can mostly avoided by simply by ensuring good air circulation, clean up old fallen leaves that accumulate under the shrub, and also avoid overhead watering. Do not use Chlorothalonil fungicides on Japanese pittosporum; this will cause the plant to lose its leaves and die. Root rot diseases can be avoided by planting in poorly drained areas. If the plant acquires a fungal infection simply remove the infected branch 6 inches below where symptoms start to show. Insects can also be a problem for Japanese pittosporum, though not untreatable. Horticultural oil sprays are affective against mealy bugs and aphids as well as cottony cushion scale.
Landscape Value Japanese pittosporum grows very rapidly and is extremely dense and tough suiting them well for the demand of the landscape industry. They are used most often as hedges or screens; however they are also used as multi-stemmed trees when lower branches are removed.
References Martin, C. A. 2015. Pittosporum tobira. Arizona State University. Online.
This document was authored by Trey Raney, Department of Agricultural Sciences, Louisiana Tech University, April 2015.