Low growers are like the glue in garden beds, holding things together and making the garden look cohesive—especially if they recur in a number of places.
Catmint, particularly if it is a low-growing variety such as ‘Little Trudy’, is a good low grower, and alyssum is another. It produces mounds of bright yellow blossoms in the spring, and then the neat grey foliage provides good contrast for the rest of the growing season. ‘Gold dust’ aptly named, is a reliable variety.
Alchemilla, 16-24” tall in zones 3 to 8, is another yellow-flowering beauty with the common name of lady’s mantle. Its flowers are chartreuse and they last well in a vase.
Columbines also provide cohesion in a bed and have the added advantage of being available in a number of pretty colors, and they often self-seed.
Arabis is another great low-growing spring bloomer. Its common name is rock cress, and it has grey-green foliage and white flowers in zones 4 to 8.
And, of course, brunnera, with its forget-me-not flowers and lovely foliage, looks wonderful repeated throughout beds, and it will take some shade.
I also love the blue-flowering campanulas, and there are a number of low-growing ones.
Dianthus are also low maintenance and come in many colors with interesting spiky foliage.
Throw in some cranesbill geraniums, low sedums, and coral bells, and you will have a collection of perennial low growers that will be the envy of the neighborhood.