Are there hints that will help search out plants that are good for growing without irrigation? Unless they say "xeric" or "drought tolerant", I'm at a loss. I've seen a lot of iris planted in graveyards, and High Country Gardens says that spring blooming bulbs don't need watering while dormant.
Where I live, we have a dry growing season. At our last frost day, when the soil isn't yet warm enough to germinate our main season seeds, our rains end. We get no rain for 6 months or more. Zip. Zero. Nada.
But it does rain here in the winter, just like around the Mediterranean.
Choosing crops that grow in a Mediterranean climate is the easiest way for me to find plants that grow here. But every place is different. What plants work for me, may not work for you. Gardening is a very local activity.
Last summer I grew squash without irrigation. This is a high-water crop. Did I mention the drought we get every summer? I did this by creating a place a bit like a hugelkulture
There are lots of different ways you can grow plants without irrigation, including air wells, berms, and more. Even plants that are 'impossible' to grow without irrigation can be grown using the right techniques.