They may not be very drought tolerant, but this plant is actually not uncommon slightly further inland from our place in Halkidiki, which is generally dry. I have seen many lush plants roadside, they are quite attractive and I never guessed that they needed much water. When I first discovered them, it took me a while to understand that they were Sambucus, since they are herbaceous perennials and not woody shrubs like the Sambucus spp. I was used to.