Photographer: B. Navez Source: Wikimedia Commons Copyright: CC BY-SA 3.0
The strawberry guava, can grow as either a shrub or a tree. If in tree form it can grow up to 20 feet, with a smooth trunk. The leaves are oblong, 2-4 inches long, dark green, and aromatic. The flowers are white, 1 in long with 4-5 petals and many stamens. After pollination, they turn into edible, golf-ball-sized, purple fruits.
Psidium cattleianum is an aggressive grower that forms shade-casting thickets, and produces many fruit. In addition to shading and crowing out native plants, their leaves produce toxic chemicals that can prevent the growth of other plant species. It is considered one of the worst plant pests in Hawaii, and is often found in sites that were disturbed by invasive feral pigs. Furthermore, in Florida it also acts as a host plant for the Caribbean fruit fly, which is a pest of citrus crops.
Strawberry guava trees spread by seeds and root sprouts. Seeds are spread from parent trees by invasive feral pigs. Studies have even shown that re-establishment of this tree is unsuccessful in pig-free areas.
It was introduced into Hawaii for its edible fruit in the early 1800s. Following that it was also introduced into Florida in the 1880s for the same reason. It was then extensively plants in Florida and were found growing in the wild by the 1950s.
U.S. Habitat: Tolerable of several different habitats including dry to moist forests, in tropical and subtropical climates. It cannot tolerate freezing.
U.S. Present: Hawaii, Florida and Puerto Rico
For a state and county distribution map provided by the USDA PLANTS database click here
The fruits on P. cattleianum can resemble the common guava (P. guajava), which has 4-angled branches and larger leaves with the veins prominently raised below.
Especially in Hawaii, the main management strategy is maintaining feral pig populations, because they help spread the plants and are invasive species themselves. Researchers are looking into biological controls for strawberry guava, but there is concern that they might attack the native common guava. Strawberry guava is susceptible to picloram, dicamba, glyphosate, and triclopyr.
Gordon, D. R. and K.P. Thomas. 1997. Strangers in Paradise, Impact and Management of Nonindigenous Species in Florida. Washington, DC: Island Press.
Hodges, C. S. 1988. Preliminary exploration for potential biological control agents for Psidium cattleianum. Tech. Report 66. Coop. Natl. Park Resour. Studies Unit. Univ. of Hawaii, Honolulu. 32 pp.
Huenneke, L.F. and P.M. Vitousek. 1989. Seedling and clonal recruitment of the invasive tree, Psidium cattleianum: implications for management of native Hawaiian forests. Biological Conservation 53:199-211.
Jacobi, J.D. and F.R. Warshauer. 1992. The current and potential distribution of six introduced plant species in upland habitats on the island of Hawaii. In C.P. Stone, C.W. Smith, and J.T. Tunison (eds.), Alien Plant Invasions in Native Ecosystems of Hawai`i: Management and Research. Univ. Hawaii Coop. Natl. Park Resour. Studies Unit. Univ. Hawaii Press, Honolulu.