Water requirements of urban plants

Abstract

Sixteen species of trees, shrubs and ground covers, commonly used in landscape designs in southern Arizona, were given high, medium, and low water treatments under trickle and spray irrigation systems. Annual water deliveries for these plant species were obtained. Well-distributed summer rains substantially reduced the irrigation needs of these plants, and all the plant species were reasonably maintained under trickle irrigation, with less than one-gallon-per-day water deliveries, except Mulberry. Plants were grouped into four categories according to their annual water deliveries, viz., very high, high, medium, and low water users. Trickle-irrigated plants made almost equal growth and maintained similar appearance as spray-irrigated plants, which were given more water. The data on plant growth increments were analyzed for selected ten plant species to determine the effects of reduced water treatments. None of the plant species showed significant linear or quadratic relationships with water levels except Privet, which showed significant linear relationship with high, medium, and low water treatments for plant height and plant spread.