for shade I always recommend Sissoo. But that's just me.

I guess my concern was more about the amount of trees and spacing. If the tree's eventually get 20-30 feet or more around how could he say we could put up to 5 trees in our backyard. The wife wants at least 3 so I gues I'm trying to figure out if it's a bad idea to plant the trees mention in our yard.

Cancel the order! There is no rational reason for those three trees to share a space.

Shamel Ash is messy and suceptible to Texas Root rot.
Very likely to damage from some caterpillar: http://cals.arizona.edu/maricopa/garden/html/t-tips/bugs/carpntr.htm

Tipuana gets 20-50 feet wide fairly quickly. Would get quite crowded.

Draw up a plan for your backyard ... dimensions and what you want to do in it, where you need shade, etc. Do you want to grow vegetables? Where will they be to get enough sun?

What do you want from a tree? Low water use? Native plant? Evergreen? Fruit? Where should it be placed to shade what you need shaded?

Take the time to look up the trees BEFORE you place an order, know what you want, and know exactly where they need to go before you even walk into a nursery. You had "sell me whatever you have in stock" written all over your shirt.

Agree with lazygardens, also wanted to add this: dont get hung up on the number of trees you want, instead use careful planning (design) to see what you will need for what you want to accomplish.

I thought I was somewhat prepared had a drawing to scale I had areas were I planned to put the trees. I had 20 foot circles were I wanted trees. Had a list of trees I wanted to look at in fairness the shamel ash and elm were on the list. Tipu wasn't on my list but had see some mentions of it as a good shade tree. My mistake was still not being informed enough about the size the trees would eventually get and listening to the nursery guy.

I know there are plant lists for low litter trees/plants for pool areas on line. Check with the County Extension office for noncommercial ideas.

This is a good time of year for a walk too. There are areas for viewing a variety of trees/plants that do well. In Phoenix I think of Desert Botanical Garden or the Glendale library. I'm sure there's lots of places.

Another thing I still do is drive through neighborhoods and look for what I like. I'm so glad cell phones come with cameras now. I try and make note of the orientation- but I figure out what it is later.

It's so confusing to keep track of what's what and I'd rather see it in a landscape anyway. I'm sure you've noticed that there is quite a difference in the quality of various nurseries also. Going to one with a good reputation can pay off. It's better to take your time and get it right than it is to have an instant landscape. I put up a 10x10' canopy for shade until I found the right tree.

I am a landscape designer in the Phoenix area and can tell you from experience that the type of nursery you go to is a major factor in the advise you get. Some nurseries pay their employees by commission only so if you dont buy they dont get paid. You need to go to a nursery that pays their employees by the hour. They are less likely to lie to you if they get paid by the hour. When I get bored I will sometimes go to these commission paid nurseries just to see what they will try to sell me and what kind of crap they feed people so I know which ones to trust. I wont send anyone to a company I cant trust. The best part is to see their face when I tell them I am a designer that knows her plants. Always do your reserch first. Know what you want to accomplish and alot of times the internet is the best place to start. Remember not everyone has YOUR best interrest at heart. Need more help please holler!!!