I'm in an Australian zone 6 which is roughly equivalent to a 7-9 USDA zone. It's a Mediterranean climate with a very hot, dry summer and a cold winter with frost but no snow.
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we are also in Mediterranean climate usually zone 7b. Elder does very well here, we even have our native blue elder which ranges from Mexico all the way up into Canada. you can definitely grow elder! some varieties may be better suited to your climate but with enough water they should do really well there!