1.) Full sun in Arizona is a lot hotter, stronger and longer than full sun in MI

2.) There's more gravel in our yards than on our roads.

3.) Oleanders are nearly impossible to remove after 2-3 years.

I would also add that our soil here is generally very alkaline rather than being acidic. Also, xeriscape plants generally don't like a lot of soil amendments (compost, etc). Here is a rather informative site about xeriscape plants, etc: http://amwua.org/landscape_plants_online.html

P.

Forget you ever knew anything about gardening. Forget every species you ever knew about. Get the Sunset Western Garden book as a guide. If they say it will grow in Zone 12, it will probably grow.(or find their website)

You have to keep track if "Chill days" for fruits varieties.

Get your plant lists from the local water company or the University of AZ. http://ag.arizona.edu/pubs/garden/mg/index.html

Water deep, water seldom after a plant is established.

Just because it's drought tolerant doesn't mean it doesn't need regular watering for the first year or two.

Mulch! And more Mulch! If she wants veggies, lasagna gardening is her friend.

Don't bother amending soils, plant natives and mulch them with locally produced compost.

Dig holes as deep as the root ball and a lot wider.

Some plants that were tricky in the mid-west really thrive here. Iris, for example, love it.

I'd buy or check out these books:

"Cool Plants for Hot Gardens: 200 water-smart plant choices for the southwest" by nurseryman Greg Star

"Desert Landscaping: How to start and maintain a healthy landscape in the Southwest" by George Brookbank

"Palm Springs Style Gardening" by Maureen Gilmer. Great pics, notions and design ideas from someone who actually gardens in a very similar climate to our own--she covers several different styles of gardens and how to do them in the Sonoran and Mojave deserts.

Good luck and keep us posted!
Take care,
Grant

Here is a link that might be useful: Palm Springs Style Gardening

What great advice! No oleanders for me and more books for me to get! I already have some by Mary Irish, I figured my favorite garden books are done by Timberpress, so I'd start there.

Keep the ideas coming. How about trees for the back yard?

How big is the back yard, and what exposure does it get and how much shade does she want? How messy can they be?

(you got lots of choices, it all depends on what she needs)

The house faces North. I'd call the yard medium to big for a urban home. The house is set close to the street, so the front yard is small. There is a big tree in front, best guess by the "roof guy" is a mesquite. There is nothing in the back yard. And I mean nothing.

My son-in-law seems like he'll enjoy yard work, so some mess is acceptable, especially if the trade off is a great tree. I tend to like plants that not everyone has.

This trip, I'll probably put the structure (trees and shrubs) in the back, and concentrate on the front. Next year I'll add to the back.

Yeah I agree with one poster about forgetting most of what you know about gardening, though not everything, but conditions are very very different here.

Any plant that requires humidity (like tropicals)... forget it! The air can be so incredibly dry here that if you leave a cutting out without water even in the shade, the next day it will literally crumble to dust if you squeeze it in your hand. This means that crowding plants together can sometimes work to create a micro-climate that retains a bit more moisture.

The sun up north is lower in the sky throught the day and the difference in day length between summer and winter is bigger. This affects what areas will be shaded and when.
There is an awesome free 3D modeling software called "GOOGLE SKETCHUP". It's super easy to use and it has built in shadow modelling that is very accurate. You can for example create a rough model of the house and other things around it using the correct orientation. Then you can enter a location (Phoenix is close enough), and time of day, and it will show you exactly what areas will be shaded. You can then make it automatically change the time in one hour increments, that way you can tell throughout the day which areas are shaded and which ones get the most sun. Anything with exposure to the west in the afternoon will have to bear the hottest arizona sun. Personally I would think that planting a row of fairly tall trees on the west/SW side to provide afternoon shade would help whatever else grows in the rest of the yard.

There is no such thing as too little sun in Arizona, and full shade is actually rare EVEN on the north side.. The sun is at a high angle (about 80 degrees) in the middle of the day.

Google "Caliche"... we have plenty of it, along with hardpan. very very backbreaking work to dig through. If you dig a planting hole, do the water drainage test to see if the water will go down. If not you might have to dig through the caliche to create drainage chimneys.

Arizona is a place of extremes. Just because it gets hot it doesn't mean it stays hot. Daily temp swings can be as much as 40 degrees. That means it could be 70 during the day and freeze at night in the winter. Ficus trees are beautiful but won't survive even a light frost (and they're water guzzlers).

Look up the Sissoo tree. It likes lots of water but can do very well on low water once established. it's a beautiful shade tree that is almost litter free and fast growing. (I planted one 2 years ago and it grew from 6 ft to about 20 ft.

Water deep and less often. In the summer I water trees about once a week, but leave the water running for a long time until there's a puddle and the water soaks deep.

soil conditions:
biggest problem is high ph. This can prevent uptake of iron and zinc especially in citrus. Chellated iron can help keep things green.
Nitrogen dissapears fast when it's hot (citrus like a lot of nitrogen)

Arizona has some pretty lax graywater laws. That means you can modify your plumbing to use some of your graywater for watering shade trees. You don't need a permit. My bathtub drains in my backyard around my trees. This goes a long way towards conserving water.
ok this is more than 3 things, but I hope it helps.