I don't have much personal experience with either tree, but if you'd like to see some mature specimens of the Mexican Plum, there are several in front of the main entrance to the student center at Rice University (I see you're in Houston!). I know they're at least 20 years old. They're gorgeous trees and smell heavenly when they're blooming. Seems like I may have read about them suckering some, though.

Perhaps consider a white blooming crape myrtle which will bloom three or four months of the year rather than just a couple of weeks. I have three of the Acuba variety that have gotten about 20 ft tall at maturity, but there are smaller ones. Many of them have beautiful fall leaf color and interestingly shaped limbs with smooth peeling bark. Just an idea ...

I think Roselee has a good suggestion. Crape myrtles are so common around here, but there's a reason for that. They bloom SOOO much longer than anything else. I love the Natchez variety with the beautiful cinnamon colored bark.

I've never much liked the look of Redbuds when they aren't blooming, but maybe that's just me. The Mexican Plum looks okay when not in bloom and does provide good food for the birds.

Anacacho orchid!

Here is a link that might be useful: anacacho orchid

here is another link.

Here is a link that might be useful: anacacho

We planted a redbud in our yard a few years back. It got to about 5 years old and I had my husband cut it down. I got tired of redbuds coming up EVERYWHERE all over the yard and in my gardens. Won't be doing a redbud again!

Thanks so much everybody! I think I'm leaning towards a Mexican Plum now after reading the comments (but I'll look into the Anacacho orchid tree as well!) I do love Crepe Myrtles, but we already have two of them in our backyard, so I'm thinking I should mix it up a bit. It's important to me that the tree be attractive even when not in bloom, so Julia I'm glad you mentioned that the Mexican Plum might be superior in that regard.. Nearly all of the pictures I've seen both trees have been shots of them at their prime, covered in blossoms, so it was difficult to compare using google images alone. Definitely taking a trip down to the Rice Campus tomorrow to check the MP in person! :)

The one MP I had bloomed for a very short time. It was beautiful. The bark had a lot of interest. you might even get some plums.

Fringe tree is a beauty. I have only seen them in photos and they are totally inappropriate for my area but they are mentioned as a good tree for Houston. There is an American Fringe tree (Chionanthus virginicus) a native, and a showier Chinese Fringe tree (Chionanthus retusus).I would plant it if I could. Does anyone out there have any experience with this tree. Another native for the Houston area is the Parsley Hawthorn tree is also a native of Houston.

Here is a link that might be useful: Fringe tree pictures

I have planted a Mexican Wild Olive (I am in San Antonio). I think it could be damaged by freezes. There is one in front of the Alamo - Beautiful. You can never go wrong with crape myrtle. I really like one called Natchez. It is a spreading tree with white blooms and beautiful bark. It might be get too large for you space, but worth taking a look at. I also got an Acoma crape myrtle. Very pretty. Might be just the size you need.

LoBro, I have both a Mexican Plum and a Redbud in my back flowerbed, love them both, but they do bloom only for a couple of weeks in the spring; if we get a late freeze that's the end of that! The Mexican Plum does sucker but not to the point that I can't handle it.

Wantonmara. I bought a Chinese Fringe Tree at a 1/2 price sale right after the 4th of July last year, went ahead and planted it, it didn't miss a beat! This spring got a few blooms, but it is still small, so can't really judge it yet.

Mexican Wild Olive (some call it Texas Wild Olive) is a great suggestion, too. I have a one-year-old tree in Pearland and it pulled through this past winter's freezes. The north side of Houston might be a bit iffy, though - I'm not sure. Buchanan's Nursery in the Heights has two beautiful mature specimens in their parking lot - gorgeous trees. They bloom on and off year round. Buchanan's also sells them.

I don't know why I didn't think of it - it's one of my very favorite ornamental trees.