Harmony - have a look on line for permaculture. Its about building a natural system that suits local conditions. lots of different things/ plants together. I visited a coastal person who had build a lot on the sandy base. her built up areas did not have a hard surround.
Some thoughts - mulch helps a lot, most places. The ash might have been too concentrated, and maybe the what was burnt had an effect too.
For garden design - start with a mud map of the yard, draw in the house, driveway, sheds, mulberry tree, concrete strip, vegie square . Think about what you want to grow.
When you cycle about look out for what others have done that was successful. In other words - what grows in that area. Talk to people. They may gift you cuttings and helpful advice.
(I would) Take most notice of those without the elaborate watering systems, though you may find that helpful if DH got onboard with drip systems instead of building houses.
I was reading last week of a permaculture course in Albury NSW that has taught students from the Amazon to Thailand, and its in an often arid place, so principles can be applied everywhere.
Thanks everyone for posting here. I need to get myself together enough to do more here and reading what you are doing helps me. I have to admit green just grows here, though not much that fruit or nuts are produced.
My neighbour was doing great with an asian style market garden, before the scrub turkeys decided it was their favorite place to scratch things out.