What about Rosemary? If kept trimmed it will stay within the range you desire, some are bushes some ramble and some are just small compact little plants. You will need to be sure they can survive in your area. Try checking with you local extension agent.

I already have 4 rosemary right near there; that much more space full of rosemary would be overkill. Yes, they survive here, and get HUGE. I don't think the prostrate rosemaries that stay low survive here; I had considered them in another spot.

Just to add one more I can't do -- chives. I'm deathly allergic.

I am reconsidering thyme or one of the greener colored diathus for the low spot. I'm still stumped for ideas on the larger one for something that's evergreen.

For the low one would Santolina virens grow in your area? The flowers are lemon yellow but if sheared over before bloom it will stay a nice fresh green dome. Iberis sempervirens would fulfil the same role and has white flowers.

Or some white bearded iris - that would give you a contrast to the blobby shape of most of the other plants and they like similar conditions to the Mediterranean herbs. (There is a herbal link via Orris root). Libertia grandiflora would perform a similar visual function, but not the herbal one.

Or some of the many hardy geraniums. The flowers are edible.

Hypericum - either the ornamental or the herb.

Flora_UK -- I have all of those plants you mentioned in the same bed (although on the other side.) Except Libertia grandiflora -- that looks like a good option if I find an empty spot in the bed as it grows up.

agmss15 - I like St. John's Wort a lot except that it's terribly invasive here. And it has yellow flowers.

I spent the afternoon nursery-hopping and ended up with silver-edged thyme and "Mr Goodbud" autumn stone crop. After getting them home, both look good in the bed. I ended up swapping their spots, though, and decided I need once more Provence Lavender and another shrub -- possibly another Ruby Loropetalum but maybe a dwarf white crepe myrtle.

*sigh* And I thought I was done! Well, at least until something does or a I decide I don't like it!.

Thanks for the suggestions. After a while your brain just can't pick one more plant!

I have a 10-year old Pink Knockout that dominates her space. Underplanted perennials that have been successful include Party Girl Japanese anemone, lysimachia (chartreuse turkey vine) and some new large-flowered St. John's wort, which are staying put and doing very well.

Garlic chives and feverfew like to grow in that bed, too, and both make nice accents as long as I don't forget to deadhead and end up with a gazillion seedlings.

I would like to advocate for a sunny, well drained spot for white horehound, just because it is good for bronchial conditions. (Black horehound is purely ornamental, and apparently somewhat poisonous.)

It is a modest plant with pretty little furry leaves, and can perennialize in my zone, so probably yours as well.