The common Guava, Psidium guajava, Many of us would be taken aback if this popular dessert fruit could no longer grace the dining table in all its many guises. The Psidium guajava, (Common Guava) has an invasive status of transformer and is classified as a category 2 declared invader (allowed only under controlled conditions). Native to South America, the Guava was introduced into South Africa as an agricultural crop. Like so many other useful plant species because of its commercial value, it too has escaped from the orchards and established itself in the wild becoming a serious invasive weed, mainly in the eastern areas of our country, particularly in KZN and Mpumalanga low-veld. Indications are that it is spreading westwards along the coast into the Eastern Cape and signs of wild plants are appearing in our area. The negative impacts of the uncontrolled infestations of the plant are twofold. The growth habits crowd out indigenous vegetation transforming the landscape and wild unattended plants act as hosts for fruit flies which in turn impact on the commercial fruit production of other fruits. Those of us with plants in our gardens for home consumption should bear in mind that the fruit is also enjoyed by birds, baboons and monkeys and to prevent the spread of Guava seed by our feathered and furry friends we need to take some precautions. The most practical method will be to protect fruit for your own use and to remove any excess fruit from your tree before the seeds become viable. This small thoughtful action on our part will contribute to protecting our natural environment while we continue to enjoy the nourishing goodness of Guavas.
Identification: The Guava is a perennial evergreen shrub or small tree. The leaves are stiff and quite thick, green-bronze in colour, oblong-elliptic, broad and rounded at both ends with conspicuous veins. The flowers are small, white in colour and in groups of one to three. The plant invades forest margins, roadsides and water-courses. Once established the Guava is not easy to eradicate. It has a strong root system, coppices when cut and produces vigorous root suckers. Ring-barking, strip-barking and felling encourages root suckering.
Control: Many unregistered herbicides are ineffective because of the robust root system. Other than the complete removal of all roots the correct use of a registered herbicide is the only solution. Chopper and Hatchet are registered for cut stump treatment and will also work with a frill. For foliar application Plenum 160 ME is registered. Please remember that the correct, responsible and careful use of herbicides is essential to avoid negative impacts on the environment and any indigenous vegetation.