In Continuous Bloom, A Month-by Month Guide to Nonstop Color in the Perennial Garden, by Pam Duthie, (Ball Publishing, 2000; $40) the author has arranged 272 perennials according to bloom time so you can mix and match them to suit your gardening taste. Duthie also describes which perennials are evergreen, provide colorful foliage, interesting texture, or have winter interest. It's an excellent resource, whether you're designing a new garden or making additions to an established bed.
Favorite or New Plant
Ligularia 'The Rocket
Ligularia stenocephala 'The Rocket' has gorgeous heart-shaped, toothed leaves that grow up to 9-inches across. It produces spires of small, yellow flowers on wiry, 5 foot tall black stems. 'The Rocket' blooms from late June through July in my area. It grows best in part shade and brightens a corner of the garden bathed in morning sunlight, but shaded from hot afternoon sun. This easy-to-grow perennial is hardy to USDA zone 4 and thrives in rich, humusy soil that holds water well.