Magnolias do well here, but beware that they get huge! Their canopy can get 30 feet wide and 40 feet tall when mature. I don't think they grow particularly fast so it may not be an issue for awhile.

Gardenias are fragrant shrubs but unfortunately can't take the cold here. They also need acid soil, while most of Dallas is alkaline. You can always have one in a pot and move it indoors in the winter, but I haven't had good luck with them. I hope you do better.

I'm in Austin and have both a Magnolia tree (5 years old and probably 20-25' tall) and what was labled a "frost resistant" gardina shrub(3 years)...either I'm lucky or both are relatively easy to grow - the gardinia is in the ground with no issues but again, I'm in Austin so it's less likely to frost here than in Dallas.

I am north of you, and the magnolia that was a "shrub" when I moved here 17 years ago is not at least 30 feet tall, and perhaps as wide. If I had known then what I know now, I would have moved it far away from my yard area (like two acres away). Besides the almost constant raking of leaves that never seem to compost, you then have the fallen blooms and then the cones. I get to enjoy it perhaps 3 months out of the year. It also puts out very shallow roots preventing my planting anything by digging. It's beauty is marred by all these things that I consider negative.

I was under the impression Gardenias are evergreen. I have 2 dwarf gardenias (in the ground for 3 years) about 3 feet from each other. The one that looks fabulous and has tripled in size is next to the fence. I wonder if that's why the other one, which is not next to the fence, looks like it's on its last leg.

I wanted a Magnolia too until I found out the same things Carrie wrote above, now I don't want one.

Please check the article Magnolia vs Gardenia: They’re actually quite different to find more information.