Succulents? If you don't water them, succulents do get unhappy, but stay a bit moist. I have an unwatered aloe vera that lives on from year to year in summer-dry California. Ice plant naturalizes at Point Reyes, which is cooler and moister than the East Bay where I live, but gets no summer rain.
https://debraleebaldwin.com/succulent-landscape/succulents-saved-day-says-wildfire-survivor/
"Clearly more research is needed, ...What I can say with certainty is that planting a swath of moisture-rich, fleshy-leaved plants is smart if you live in a mild, arid region plagued by drought and wildfire. Readily available agaves, aeoniums, elephant’s food, aloes, jade, and ironically-named ‘Sticks on Fire’ propagate easily from pups and cuttings, are low-water and low-maintenance, and when combined, create a gorgeous garden. If it also serves as a firebreak, well—as I told a KFMB-TV reporter—that’s certainly icing on the cake."
