OSBECKIA OCTANDRA: A POTENTIAL SHRUB FOR URBAN ENVIRONMENT

Abstract

The urban landscape is characterized by altered climate, water relations and soil conditions. Governments spent millions of dollars in maintaining such landscapes. A landscape developed with sustainable practices can reduce this cost and improve the environment. In this context native plants can play a major role as they survive in local environments and easily adapted to local conditions with a minimum maintenance cost. Further, the landscape industry is continuously in need of novel and exciting material to maintain the viability. As a solution, floristic wealth of Sri Lankan flora can be successfully tapped to introduce native plants to urban landscapes. Based on field experience Osbeckia octandra was identified as a potential landscape plant. Therefore, the present study was conducted with the objective of identifying the landscape potential and a method to propagate O. octandra in order to popularize it as a landscape plant and to introduce into the landscape industry. Morphological characters and flowering phenology were observed and a propagation experiment was conducted using three types of cuttings (softwood, semi hardwood and hardwood) vs. two types of media (sand, sand 1: coir dust 1) arranged in a randomized complete block design. Osbeckia octandra is a fine textured small shrub with spreading habit and it tolerate pruning and it can be ideally used in a border. Flowers are attractive, purple in colour (purple group 77A, RHS color chart) and produce flowers at least four times a year which attract insects. A significantly high (P<0.05) growth performance was recorded in hardwood cuttings. However, a significant difference (P<0.05) was not recorded among potting media. Therefore, hardwood cuttings grown either in sand or sand with coir dust media can be recommended as the potential propagule and potting media to propagate this plant.