Having a garden filled with spring-to-fall-blooming perennials may seem to be an elusive dream. Many perennials put all their energy to flowering over several spectacular weeks in spring, summer or autumn, while some briefly figure out how to bridge two seasons. The good thing is that other perennials start blooming in spring and last until autumn’s shortening days ship them to dormancy. These botanical marathoners ask just for the right growing situations to keep them at their summit.
Fortnight lilies and African American irises (Dieites bicolor, D. iridioides) thrive in U.S. Department of Agriculture plant hardiness zones 8 through 11. The sword-leaved, evergreen perennials like sunny to partially sunny sites with averagely fertile, well-drained dirt. Intricate, iris-like flowers of white with yellow markers and pale-blue inner petals crown fortnight lily’s rigid, 2- to-3-foot stalks. African irises create soft-yellow, maroon-spotted blossoms. While the flowers last only 24 hours, fresh ones open as old ones fade. Removing the seedpods as they appear encourages continuous flowering. The plants spread by fleshy roots called rhizomes to form 3- to 4-foot clumps. Root division every three or four years maintains their vigor.
Daisy-flowered tickseed cultivars put the perennial border ablaze from front to rear. Dainty “Tweety” (Coreopsis “Tweety”), suitable for USDA plant hardiness zones 5 through 9, produces 14- to 16-inch mounds of dark-green, finely-cut leaf covered in chrome-yellow blossoms. Red-centered, golden-yellow flowers adorn 2 1/2-foot “Gold Nugget” (Coreopsis “Gold Nugget”), a good choice for USDA zones 6 through 10. Stately, 4-foot “Rising Sun” (Coreopsis “Rising Sun”) rises in USDA zones 4 through 9, with golden-yellow flower petals which have red-spotted bases. These drought-tolerant, butterfly-attracting perennials flourish in full sun and dry, loose, well-draining dirt. Deadheading their spent flowers keeps the brand new ones coming.
Sun-loving, heat- and drought-resistant guaras (Gaura lindheimeri) bloom from spring to fall in USDA plant hardiness zones 5 through 9. Rank 20 inches to 3 feet high, the vase-shaped plants create loose clusters of elegant, butterfly-shaped blooms from pink buds that are dense. Their narrow, lancelike green leaves sometimes possess maroon speckling. The “Geyser White” and “Geyser Pink” cultivars (G. lindheimeri “Geyser White, G. lindheimeri “Geyser Pink”) provide silver-white and deep-pink flowers, respectively. Guaras enjoy sandy or loamy well-drained soils.
Alstroemeria (Alstroemeria spp.) Lilies, reliably hardy to USDA zones 8 through 11, create azalealike blooms climbing on clumps of arching, deep-green leaves. Happy in moist, deep loam, they require regular spring and summertime irrigation tapering away in fall. These non-stop performers bloom in a plethora of white, yellow, orange, purple and pink shades, often with variegated spotting or streaking. The Princess alstroemeria collection, ideal for border fronts or containers, grow 8 to 15 inches high and wide. “Zapriamin” (Alstroemeria x “Zapriamin”) bears glowing, strong orange blossoms. It makes a festive screen combined with royal-purple “Zaprinous” (Alstroemeria x “Zaprinous” P.P. # 15987) and orange-striped, golden-yellow “Zapridapal” (Alstroemeria x “Zapridapal” P.P.A.F.). Alstroemerias like full sun in coastal locations and partial shade where summers are warm.