Chartreuse euphorbia ( Euphorbia characias Bruce 's Dwarf ) , purple Verbena bonariensis and Spanish lavender , and bright orange Epilobium canum provide spring or fall blooms that stand out against a richly textured backdrop of green , gray and white foliage such as acanthus , the westringia Morning Light , the pittosporum Compacta , the phormium Tricolor and Dudleya pulverulenta .