Take a look at Parkinsonia 'Desert Museum'. The only issue may be the drainage, but you can plant it high. Here it flowers from May-August, attracts pollinators and hummingbirds and has wonderful winter interest with its green bark and stems. Native to Arizona. This photo is of two of mine, taken mid-July. They are still fairly young trees.

Is there a reason an evergreen would not work? I'd consider Arbutus unedo or Arbutus 'Marina'.

Thanks for the replies.

I'll check out the Sunset Western Garden Book today at my local library. It seems like a good reference.

Sara, the Parkinsonia 'Desert Museum' looks beautiful. Attracting pollinators and hummingbirds is a major plus. But it looks like it would provide dappled shade at best. Are there leafier versions? I hoping to provide enough shade to cool the paved area around it.

The patio is close to a large south facing window which lets the low winter sun in. That's why I'm looking for a deciduous tree. Otherwise, (excepting also a rather slow growth rate) Arbutus is very attractive.

Nothing leafier but this does a reasonably good job (I've pruned off quite a few branches as I want to be able to look through them). It isn't a tree that will create deep shade like a mulberry, though. Google it and look at images. You'll see how dense some can be if not pruned.

Thanks. I've already envisioned another couple of places where I want to put this tree.

Also, do you (or anyone) have any experience of Trident Maple and Shantung Maple's growth rates in this climate zone (USDA 9b, Sunset 15)? I see conflicting information online ranging from slow (12") to moderate to fast (36").

The J Frank Schmidt Acer truncatum x A. platanoides maple hybrids are being planted in numbers on streets here. These seem to develop pretty rapidly. Inquire locally to see if they appear to be suitable for use where you are. Currently Schmidt lists and describes 5 different named selections.

http://jfschmidt.com/introductions/index.html

5x7 seems awfully small. The roots of anything you plant will quickly fill that area and begin to grow into the surrounding soil, under the paving.

We have a Trident maple in our yard, planted as a tiny seedling about thirteen years ago. It was selected from a collection of volunteers from a gorgeous mother tree and we hoped that the gene pool was a strong one. We crossed our fingers for a great natural infrastructure or beautiful fall color.....we got both.

The seedling was about two feet tall when I transplanted it into a bark based potting medium to grow for a year before planting it in our side yard. It was about three feet tall when planted in the ground. It's now approx. 30 feet tall by 25 feet wide, with a diameter of 14 inches. (I asked my husband to go out and look.)

We plant directly into hard, red Alabama clay soil with no irrigation under two to three inch layer of mixed wood mulch that we increase the radius of every year as the tree shades out more of the lawn. It does get watered during periods of serious drought, maybe a handful of times a year, at most.

I live in Northern Alabama (6b-7a), with coldish winters and I consider this a pretty sunny part of the country.....certainly not gloomy.

There are no visible surface roots and no driveway buckling. I asked my husband about the mature Tridents where he works and he said that there are no pesky surface roots. He's the Director of Horticulture and Landscaping at a local university in our city, so notices those kinds of things.

However, all bets are off regarding behavior of any kind considering that very small planting site.

Maples invariably crisp in our bone-dry summer air. I would plant something that can emerge from our summers looking nice.

Check Cal Poly SLO's SelecTree for "Root Damage Potential" = Low. As rhizo says 5-7' of space is not a whole lot.

Lagerstroemia 'Natchez'?

Lagerstroemia would work. And Natchez makes a reliable crown for a relatively small tree, especially if done as a standard.

Thank you for the suggestions. I suppose Natchez is a good option.

One more question. Is there a more well behaved alternative to Robinia Purple Robe with non aggressive roots, stronger structure but similar form/habit?

Nope. Not in that genus or with that habit. You might look at some Acacias, though. A. stenophylla, for example. Some get bigger/grow faster than others.