Try it in the shade with a little lime in the soil.

We have new house and landscaper planted 3 vitex/chaste trees. I'm not familiar with it, but supposedly it's very hardy and puts out blue blooms. We just moved in November, and since it is deciduous, we have not seen it in its full glory yet. It's just now started sprouting tiny green leaves - I can't wait. It can grow in zones 6-10, so you might want to check it out.

If you like butterfly bush, see link below.

Amsonia 'Blue Star'
http://www.plantdelights.com/Catalog/Current/Detail/04225.html

Maybe a Caryopteris (bluebeard)?

Here is a link that might be useful: Buddleia 'Ellen'

Wodka, I think you will LOVE the chaste trees! They're beautiful and very hardy. If you've traveled along Hwy 17 in Mt Pleasant/Charleston, SC, you've seen them planted in the medians and alongside the road. While the flowers do resemble butterfly bushes, the trees are stronger and more disease resistant.

I have one that I grew from a seed I got in a swap here on GardenWeb. After a few years, it hadn't bloomed. I did a little research and learned that trees grown from seeds take five years to bloom. It was year five, and it bloomed! I've enjoyed it very much and have others now.

paulacat - thanks for the info. The chaste trees are getting greener with each passing day. I have never been to Charleston (would love to, though!) but I bet they're beautiful there.

I've just had the winter view of them so far, but I even like the shape of the limbs, bare and all during the wintertime. Kind of reminds me of what a miniature crape myrtle would look like.

Once I get some blooms, I'll post a picture here.

Salix purpurea 'nana' (dwarf blue willow)should grow in Wilmington if you give it a little shade. We grew them in Atlanta with a little lime and an eastern exposure. They would probably burn up on a southern exposure with reflected heat.