FOR SOUTHERN CALIFORNIA AND HAWAII
Aster. A. x frikartii 'Mönch' is on everyone's top 10 list of lavender blue perennials; plants grow to 2 feet. Sunset climate zones 2b-3. New England aster (A. novae-angliae) has mostly blue flowers. 'Alma Potschke', an old favorite, bears salmon pink blooms. Grows to 3 feet tall. Zones 1-24. Flowers of Michaelmas daisy (A. novi-belgii) come mostly in shades of blue; 'Climax' has true blue flowers. Grows 4 to 6 feet tall. Zones 1-24.
Bat-faced cuphea (Cuphea llavea). Red and purple flowers that look like bat faces appear on plants 2 to 3 feet tall. Zones 11-13, 21-24, H1-H2.
Boltonia asteroides. Bears white, pink, or blue flowers on plants 5 to 6 feet tall. Zones 1-24.
Chrysanthemum. Florist's chrysanthemum (C. x morifolium) bears flowers in many colors, from rust and wine red to orange and golden yellow. Grows 1 to 6 feet, depending on variety. Zones 2-24. C. x rubellum flowers come in various colors; 'Clara Curtis' is bright, clear pink. Grows 2 feet tall. Zones 1-24.
Coreopsis. C. lanceolata produces yellow flowers on plants 1 to 2 feet tall. C. verticillata has yellow, daisylike blooms; 'Moonbeam' bears pale yellow blooms. Grows 2 to 3 feet tall. Zones 1-24, H1-H2.
Daylily (Hemerocallis hybrids). Comes in various colors; look for reblooming or late varieties. Takes partial shade in hottest climates. Standard kinds grow 2 1/2 to 4 feet tall. Zones 1-24, H1-H2.
Gaillardia x grandiflora. Daisylike flowers in golden yellows, reds, and bicolors; grows 2 to 4 feet tall. Zones 1-24, H1-H2.
Garden penstemon (P. x gloxinioides). Many kinds and colors bloom most heavily in spring but will repeat bloom in fall if you cut back plants after flowering. Blooms range from fire engine red to deep purple to pale pink, depending on variety. Plants grow 2 to 4 feet tall. Zones 6-9, 14-24.
Heliotrope (Heliotropium arborescens). Vanilla-scented, purple flowers on plants 1 1/2 to 2 feet tall. Prefers partial shade in warm climates. Zones 15-17, 23-24, H1-H2.
Lion's tail (Leonotis leonurus). Mint family relative from South Africa bears dense whorls of tubular, deep orange flowers along spikes on 4- to 6-foot-tall plants. Zones 8-24, H1-H2.
Rudbeckia. R. fulgida 'Goldsturm' bears golden yellow blooms on 3-foot-tall plants. Gloriosa daisy (R. hirta) grows 3 to 4 feet tall. 'Indian Summer' has single to double golden yellow flowers. Zones 1-24.
Salvia. Many kinds bloom in late summer and early fall. Anise-scented sage (S. guaranitica) bears cobalt blue flowers, attractive to hummingbirds, on plants 4 to 5 feet tall. It can take partial shade in hot climates. Zones 8-9, 14-24. Autumn sage (S. greggii) flecks itself with flowers in many shades of red, white, and rose on shrubby, 1- to 4-foot plants. Zones 8-24. S. azurea grandiflora bears azure flowers, grows to 5 feet tall, and needs support. Zones 1-24. Eyelash sage (S. blepharophylla) puts out orange scarlet blooms on plants 1 1/2 to 2 feet tall. Zones 14-24. Mexican sage (S. mexicana 'Limelight') has spikes of showy yellow green stems and calyxes with cobalt blue flowers on plants 3 to 5 feet tall or taller. Zones 9, 14-17, 19-24. Mexican bush sage (S. leucantha) has velvety purple flowers on plants 3 to 4 feet tall. Zones 12-14, H1-H2. Pineapple sage (S. elegans) has bright red flowers and fragrant foliage on plants 3 to 4 feet tall. Zones 8-24.
Sneezeweed (Helenium hybrids). Flowers in red orange. 'Moerheim Beauty' is coppery red. Grows 3 to 5 feet tall. Zones 1-24.
Star cluster (Pentas lanceolata). Flower stems are topped with tight clusters of star-shaped flowers in white, pink, lilac, or red on plants 2 to 3 feet tall (6 feet in Hawaii). It's a favorite of butterflies. Zones 23-24, H1-H2.