While blue goes with nearly every other color, it is not always easy to find perennials with blue flowers that grow vigorously.
There are bulbs, of course, and one can never have enough blue hyacinth or grape hyacinth flowers! There is still time this fall to plant lots of grape hyacinth bulbs. Their foliage appears in subsequent years in the fall and serves as a marker to remind gardeners where they are. This is a great help, as we all hate to slice into previously planted bulbs when we are planting new ones.
Because of this, I always plant a few grape hyacinth bulbs with any other type of bulb that I am adding to my garden each fall.
I am planting more of the tiny blue scilla bulbs this year. They bloom very early and naturalize to form carpets of blue, even spreading well in the grass lawn. The tiny bulb flowers, like snowdrops, that appear so early each spring are quite special, and Glory-of-the-Snow is another winner in this category.
And if you don't already have some Virginia bluebells in your yard, try to get some of those next spring. This is a native plant that was first found in Virginia, though it grows in many parts of the U.S. and naturalizes well in partial shade under deciduous trees since it blooms before they leaf out. These bluebells grow about two feet tall and in the spring produce bell-shaped flowers that start out pink and turn a glorious blue. They die down after they bloom and disappear, but often one finds that the next spring they reappear in even greater numbers and it is such a heaven-sent (or scent?) bonus!