You just cannot go wrong with Calamagrostis acutiflora Karl Foerster (green) or Overdam (variegated, slightly shorter). With blooms it will get to about 5' tall. It has a couple of interesting bloom stages and is completely non-invasive. Best of all, it's a cool season grass so it wakes up and starts growing quite early. Cut it down once a year in the spring, and that's it. I have never watered mine - just whatever the sky brings is what they get. No fertilizer required, either. Here's a pic of it in my yard

You can grow tall pampas grass, etc. if you grow them in a container. The key is to give them TONS of room for roots and feed with lots of manure and water. Those big plastic containers for small trees are good and they an be spiffed up with a covering or placd among tall plants.

For a perennial I second pudge's recommendation above.

Thanks Alpiner and Pudge. That's really good information. I think I'll try both. I actually started pampas grass as an experiment in the house and will try growing some in a container.

That's a great picture of Karl Forrester Pudge. I'll try it in my garden. Like that it's really low maintenance and a good height. Hope your gardens grow well this summer !!