Results

Shrubs planted from 3-gallon containers can be established with 3 liters irrigation applied every 8 days in north and central Florida and every 4 days in south Florida under normal rainfall conditions, but increasing the irrigation frequency to every 2 or 4 days may increase shrub growth for some species.

Irrigation frequency treatments did not significantly affect shrub survival or quality (canopy density and dieback).

Most shrubs reached a point when regular irrigation could be discontinued between 12 and 28 weeks after planting as defined by reaching a root spread to canopy spread ratio of 1.0 or greater.

Time needed for shrubs to reach a root spread to shoot spread ratio of 1.0 varied considerably by species.

Supplemental water was required after irrigation was discontinued from 2-5 times depending on the hardiness zone up to 2 years after planting. Shrubs should therefore be monitored for symptoms of water stress during the first 2 years after planting.

There were no differences in growth or quality between native and non-native shrubs as group in any hardiness zone planting.

Survival of some species was significantly reduced when irrigated every 7 days under a rain shelter, but not when irrigated every 2 or 4 days. This suggests that sufficient rainfall is needed to supplement irrigation at frequencies used in this study for some species.