Irrigation Needs of Ornamental Plants in California

Ornamental Plants

• Ornamental plants are chosen for their aesthetic value and that means a wide variety of plants species may be present at one site, with different water requirements. Drought has an effect on the appearance of ornamental plants, and makes them vulnerable to insects and disease.

Irrigation Guidelines

• Group plants with similar watering requirements together. Water deeply and infrequently to encourage strong roots; the whole root zone should be be wet. Light watering inhibits deep root growth and increases drought stress. Over watering is also harmful. Tree and shrub irrigation zones should be separate from turf; they need less frequent watering.

Water Use by Species

• A list that classifies plants according to whether they need high, moderate, low or very low amounts of irrigation has been published by the University of California Cooperative Extension and the California Department of Water Resources. Many landscape plants' irrigation needs were evaluated from field studies, but not all regions of California were included (see Resources).