Dianthus? Armeria? Campanulas? Sage? Lavender? Golden Oregano? Geranium sanguineum or other small Geraniums?

Is doing 75 feet in one type of plant really what you want? How about a mix of three or four plants repeated? That way if disaster strikes you don't lose the whole lot.

I have Stokesia/Stokes aster at the edge of two part-sun beds. I like the elongated foliage that isn't bothered by pests. I would also second the dianthus with its blue/green, airy foliage. Growing along the edge of one walkway are two perennial geranium (G. sanguineum) 'Biokovo' (white flowers) as well as a lavender cultivar. All are trouble, pest & maintenance-free.

Have you tried Heuchera/coral bells or Alchemilla mollis/Lady's mantle? Heuchera is available in multiple colors ranging from butterscotch to strawberry to black and 100% trouble, pest & maintenance-free.

For a foliage contrast, I believe Japanese sedge grass is also available in different colors/forms. Stachys/lamb's ear 'Helen Von Stein' offers velvety, zero-maintenance silver foliage. It's a non-blooming variety and doesn't self-seed.

Here is a link that might be useful: Stachys

I have thyme, cranberry, dianthus, campanula, and Iberis all as edging in flowerbeds. Depending how wide a space you have, other things that might work include some of the smaller Veronicas like V. 'Georgia Blue' or a shorter catmint/Nepeta variety.

I have a nice hedge of Iberis that defines a planting area. I have also had Coreopsis Nana . Sadly I had to let the Coreopsis die due to our drought.

I have nepeta 'kit kat', lambs ears and short daylilies. Bunnies ate my dianthus.

I use creeping Phlox and passalong sedum that is about 3-4" tall and Ajuga reptans to edge my garden beds.

This post was edited by pitimpinai on Mon, Jun 30, 14 at 13:38

If you could stand an annual, there are wonderful low-growing zinnias that come in lots of colors and bloom nonstop all summer.

Martha

I have dianthus planted as edging in one of my flower beds. They have filled in quickly since I planted them mid April and are blooming their heads off.

Creeping sedums, spreading sedums, I have one that forms a low growing circle. Dwarf Shasta daisy Snow Lady, dwarf daylily, alpine strawberry, false lamium Herman's Pride, coreopsis rosea, hosta, 'Golden Edger'", short salvias, s. Purple Rain has a long bloom time with deadheading. It has a relaxed habit cascading along the edge of the bed. I have my long driveway bed edged with nepeta Tiltch. After first bloom it is cut back for repeat bloom.

I use these and many of the ones others have suggested. My favorite are various dianthus, especially the mat forming ones. One variety is half an inch high and looks like a carpet of bloom with its airy one inch high blossoms.