Parkinsonia praecox can be propagated from seed (3). However, since it readily hybridizes with other Parkinsonia species, it is difficult to ensure seed is true to type (2, 3). Many trees sold in commercial nurseries as palo brea are actually interspecific hybrids resulting from a cross between palo brea and other Parkinsonia species (2). In contrast, cutting propagation ensures genetic uniformity. It is recommended for Sunset heat zone 10-14, 18-20 and USDA hardiness zones 9-11 (tolerant to -6C/20F) in arid climates (2). Some sources indicate it is semi hardy and will suffer damage at temperatures below -4C/25F (1, 3, 5) while, many individuals report hardiness into USDA Zone 8a (10-15F). It prefers full sun, minimal or monthly water (in summer) once established, slightly alkaline soil with good drainage (1, 2).
Pruning is usually necessary in uban areas where overhead space is limiting – this ensures irregularly angled branches/tree are properly directed and to create a sound tree structure (5). It has a moderately fast growth rate, but if overwatered, the trees will grow vigorously and become vulnerable to failure (2, 5). Palo brea is also susceptible to problems such as mistletoe and palo verde beetles (1, 5). While most species in Fabaceae have a symbiotic relationship with soil bacteria that supports nitrogen fixation, this species is said to be devoid of such a relationship (3)
