Determining a landscape plant database matched to hydrozones for South Africa

Leslie H. Hoy1, Leslie R. Brown2, Richard M. Hendrick2 and Alan S. Barrett2

1Rand Water, PO Box 1127, Johannesburg, 2000, South Africa. 2 Applied Behavioural Ecology and Ecosystems Research Unit, Department of Environmental Sciences, University of South Africa, Pretoria, South Africa.

DOI: https://doi.org/10.37855/jah.2021.v23i01.06

Key words: Hydrozone, ornamental landscape, plant database, plant coefficient, plant factor, indigenous plants, exotic plants
Abstract: About 27 % of available water in South Africa is utilised in the urban environment. Estimates for South Africa place ornamental landscape water use as high as 50 % of urban water use. South Africa’s average annual rainfall is approximately 495 mm. Rainfall patterns are erratic with periodic droughts of anticipated increased frequency. Ornamental landscapes require additional watering to minimise impacts of dry periods. These landscapes are often over- rather than under-watered. One method of reducing urban ornamental landscape water use is to group plants according to predefined hydrozones to optimise water use through improved site maintenance, landscape design and irrigation application. Currently no extensive researched database of commonly grown ornamental landscape plants linked to hydrozones exists for South Africa. To produce such a plant database, an analysis determining the hydrozone rating of plants sold in South African nurseries was undertaken. The result of this study is a database of plant species suitable for ornamental landscape hydrozones (high, medium, low and very low water requirements) and linked to a plant factor. This provides South African Green Industries Council members, especially landscapers with a database to assist in selecting the most appropriate plants for each hydrozone for their ornamental landscapes and gardens. The database will support South African ornamental landscape water use models.



Journal of Applied Horticulture