What about lavendar or some kind of sage? Lemon balm would return (perennial) - but with a vengeance - flowers are teeny but leaves are fragrant when crushed. Feverfew puts out nice flowers in late summer and can be fragrant when crushed. Mums? I don't know anything that will give off a scent as aromatic as lilac or lilies without at least having you brush against it.

As an annual, maybe some scented geranium?

Miniature boxwood is pretty but neither fragrant nor flowering. It's also very traditional.

If you haven't already, post your query on the herb forum. Sounds like an herb would be a good choice but I don't know which ones fit your height requirement.

Thanks for your suggestions. I've been doing annuals and would like to have something come back naturally. The area is edged in boxwood so it would need to something different. I'll try the herb group to see if they have any other ideas. Thanks

Bergarten Sage grow well here in S. Central PA, and usually returns for several seasons. It can get a rather fantastic looking, large flower that is on top of a large stem. It is a handsome plant, too, unlike ordinary garden sage, which is great in its way, but not as obviously decorative.