Have you checked Bluestone Perennials or Santa Rosa Gardens' websites? I know Bluestone has pre-planned gardens with plant suggestions, many of which mirror pitimpinai's list above.
As pitimpinai pointed out, few perennials have the extended bloom habit of annuals such as marigolds and zinnias. I created a chart on which I identified various perennials by bloom period and now my garden starts blooming in March (Hellebores/Lenten roses) and continues into October (Tricyrtis/toad lily).
An ornamental grass, perhaps less impressive size-wise than Miscanthus, is Calamagrostis/feather reed grass 'Karl Foerster.' It has a tidy, upright habit and doesn't take up as much real estate as Miscanthus. Dwarf fountain grass (Pennisetum alopecuroides) 'Hameln' is an elegant, low-growing (2 1/2 ft.) grass that requires nothing more than a haircut in Spring. Deer have never bothered either grass in my garden.
You might also consider checking out a book or two on perennials from your local library as an additional resource. I found it to be an excellent source of information when I was planning my garden beds.
It's been my experience that most of the items listed above are not on a deer's menu. I have all but a few of them growing in my garden beds and the deer prefer my sacrificial hosta to any of the listed plants.
Platycodon grandiflora/balloon flower is available in blue/lavender, white & pale pink.
Dicentra spectabilis/Bleeding Heart is available in a white ('Alba') variety.
Geranium 'Rozanne' blooms until frost sometime in October and is a blooming machine. The flowers are pinkish/lavender.
Hemerocallis/daylilies bloom in a rainbow of colors that include cream and white. I have a lovely creamy white one called 'New Falling Stars.'
Some others you might want to consider:
Agastache/anise hyssop blooms most of the growing season in feathery plumes of lavender.
Caryopteris x clandonensis/blue mist shrub blooms late (September) in lovely, feathery plumes of blue that attract pollinators.
Cimicifuga racemosa/black snakeroot has white plumes in August.
Check out Aquilegia/Columbine for both white and blue varieties. It's a spring bloomer.
Gaura lindheimeri/wandflower is a delicate and elegant bloom on thin stems that wave in the breeze. Mine is blooming now and will continue until frost. The bees love it.
Liatris spicata/gay feather/blazing star blooms purple or white and is another favorite of pollinators.
Lobelia siphilitica/great blue lobelia is another that's popular with pollinators.
Perovskia atriplicifolia/Russian sage is a maintenance-free perennial that blooms mid- to late-season in both purple & blue.
Nepeta faassinii 'Walkers Low'/catmint blooms early and continues all season with zero care.
Stokesia laevis/Stokes’ aster blooms mid-summer with large, frilly blue/lavender flowers that attract pollinators. It's also low-maintenance.
Veronica spicata/spike veronica/speedwell also blooms mid-summer, has a long bloom period and attracts pollinators.
FYI--none of the plants identified above require any help from me to thrive--once established, they're all self-sufficient in healthy garden soil.
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