Phx, Az, USA - Zone 10
Thanx to a Google group gardener's suggestion, I've begun to add really deep - two foot deep - layers of mulch to my beds. I've asked my neighbors, and they've been very graciosly leaving the bags of their grass clippings out for me. So I cheerfully go door-to-door on Mondays and drag home these huge bags. I never thought other people's yard trash would make me so happy!
Wow, what a difference! Soil stays moist longer, plants are holding up to the hotter days, I don't have to water as much. I also don't have to weed as much, and I have a nice soft place to walk when I'm weeding or tending.
I've buried my soaker hoses under the mulch, instead of irrigating in hill-n-valley tradition, and that's a huge water saver.
If anyone has any tips for saving water while maintaining a big garden, please let me know. For the first time, I'm actually counting and measuring gallons, and it adds up REALLY fast.