Drought Plants

I've been given a project to improve the chapel garden at the hospital. The hospital grounds have previously had a good irrigation system, but Israel has had 5 years of drought over the last 6 years. The level of Galilee has dropped to a dangerous level and the cost of water has gone up. So with my limited gardening experience I have been taking cutting and seedlings from all the plants that survive the waterless summers: rosemary, lavender, palm trees, olive trees, cactus and many more unknown plants - my plant knowledge is poor. More than 50% are surviving. I planted them in the spring and I was told that if you get them through their first summer then they should survive, so hopefully they will grow. Now is the time for the olive harvest, we have one tree, but our neighbour has a few more and she is more skilled in picking the olives. P