To tell you the truth, most plants whether it be trees or shrubs or bedding will require very little water once they're established. There are exceptions eg hydrangeas require a fairly wet root run whereas palargoniums, begonias, gazanias, mesembryanthemums and quite a few shrubs don't mind the dry.
Generally speaking, most plants which are grown in mediterranean climates but are hardy will do well. Rosemary and lavender....as well as most other herbs will love warm, dry conditions but they must be allowed to get established first.
That's why it's always best to plant stuff in winter when the plant is dormant, and when spring arrives, the plant will start growing and hopefully the weather will be wet and warm...thus establishing the root system for the summer.
This obviously applies to plants that are grown in the ground.....tub grown plants will require dailiy watering whatever they are.
Good luck