Jerusalem thorn is a small tree growing to 25 ft. A spectacular display of clustered pealike flowers in spring makes the whole tree look like a giant yellow bouquet. Jerusalem thorn does well on sandy or gravelly soils, and is tolerant of alkaline and chalky soils. Full sun.Drought tolerant. Survives in regions that receive less than 12 in (30.5 in) of annual rainfall. Is damaged at temperatures below 18ºF (-7.8ºC).