You need to rethink your focus if you want 'permanent' container plantings - from flowers to foliage. Foliage variations in size, color and texture can provide all the interest of flowering plants but with much more of a year round approach. You can always reserve pockets even in permanent container plantings for some seasonal flower color, but it's not going to be (or shouldn't be) your focus. If you select carefully, some perennials will produce modest flowering over a very long season - some hardy geraniums, low campanulas ('Birch's Double') and Veronica umbrosa 'Georgia Blue' come to mind. But evergreen perennials like euphorbias, hellebores, heucheras, bergenia, various groundcovers, ferns are all great container subjects and will offer a lot of interest from foliage as well as flowering in their time.

Many Dianthus are evergreen, have gray foliage visually compatible with other gray or silver leaves as well as purple ones. These are common here, given sun and drainage there is little reason to think they will not do well.

I think if you're going to grow it in a container, as long as it has good drain holes, you don't have to worry about "wet-feet". My pots have the opposite problem... in the summer heat, there are times when they need watering every day, sometimes twice! (Use commercial "potting soil" rather than soil from the garden -- drains better.)

I've never tried Dianthus in a container but all have died in my garden.

I second foliage, especially Huecheras, grasses, heathers and conifers.

Geranium 'Rozanne' is a long bloomer, I've had a little blue eyed grass 'Lucerne' blooming for months now, Stella d'Oro daylilies are considered common by most but they do put on a long show of bloom and are small growers.

Bookmarking this thread. Thank you everyone!

Oh, yeah - forgot the grasses!! I'm not sure you can have a great container planting without some sort of grass or grass-like plant :-) Their textural contribution is huge.

Coreopsis & Scabiosa bloom all summer in the sun.

In the shade, try corydalis. Perfect for a container since it loves to seed. It's the longest blooming perennial in my garden. In a protected spot, it will bloom almost all year.

For a touch of black how about Ophiopogon planiscapus, black mondo grass, this looks great all year long, pink flowers in the summer and black berries in the fall and winter. I do grow some Dianthus in containers with great results as well.

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