Heliotrope

A bold, clump-forming evergreen perennial from South Africa, grown for big rounded umbels of trumpet-shaped blue (or white) flowers held on tall bare stalks above arching, strap-shaped leaves in mid-to-late summer. It is widely sold as "lily of the Nile," but that is a misnomer - the plant is South African (the Cape provinces and KwaZulu-Natal), not from the Nile. Spectacular and easy in warm climates, this evergreen Agapanthus is frost-tender, so in cold-winter areas it is grown in a container and overwintered under cover. The RHS has given several Agapanthus praecox forms its Award of Garden Merit and rates this evergreen species half-hardy (H3 - needs winter protection).

Anise-scented sage is a tall, upright perennial in the mint family (Lamiaceae), native to Brazil, Paraguay, Uruguay, and Argentina. NC State Extension and Missouri Botanical Garden PlantFinder describe a bushy, square-stemmed plant 2 to 5 feet tall and wide that carries spikes of deep blue, two-lipped flowers with purple-blue calyxes from July into fall; NC State calls it a reliable nectar source for hummingbirds and butterflies, and notes that carpenter bees rob its nectar by biting a hole in the floral tube. The 'anise-scented' name is only partly earned: Wikipedia describes 'an anise scent when crushed,' but Missouri Botanical Garden PlantFinder says the bruised foliage has a very mild aroma with 'very little if any anise scent.' It spreads by tuberous roots that let it reproduce vegetatively (NC State Extension), so it fills a space rather than staying in a tidy clump. It is winter hardy only to about USDA zone 8a: farther north, grow it as an annual or overwinter cuttings indoors, though NC State notes the 'Black and Blue' cultivar is hardier and will survive milder zone 7 winters if well mulched. Neither NC State nor Missouri Botanical Garden documents an edible use or a toxicity hazard. NC State records, as ethnobotanical history, that the Guarani people of Brazil used it as a sedative; that is not a recommendation to take it, so treat it as a non-food ornamental. It has also naturalized outside South America (Wikipedia records it in New Zealand and Chile), so where winters are mild enough for it to persist outdoors, check your local weed or invasive-plant list before planting it.

A clump-forming herbaceous perennial grown for its showy late-season flower heads: masses of tiny star-like flowers borne in flattened cymes 3 to 6 inches across that emerge rosy pink, deepen to rose-red, and fade to coppery-rust as they die. Gray-green, fleshy, succulent-like leaves form upright clumps to about 24 inches. Easily grown in dry-to-medium, well-drained soil in full sun, it is drought tolerant and attracts butterflies, and its foliage and dead inflorescences persist into winter for added interest.

The classic clove-scented carnation, a short-lived evergreen perennial in the pink family grown for centuries for its frilled, spice-fragrant double flowers and tidy mounds of narrow blue-gray foliage. Native to the Mediterranean region, it thrives in full sun and lean, sharply drained, neutral-to-alkaline soil with steady but never soggy moisture, and is hardy in USDA zones 6a-9b. It is the florist's carnation and the parent of countless border and perpetual-flowering strains, prized as much for cutting as for the garden.

A tuberous-rooted member of the aster family native to Mexico and Central America, grown for showy summer-to-fall blooms in nearly every color except blue. Hybrids in commerce span ten flower-form groups (single, anemone, collarette, waterlily, decorative, fall, pompon, cactus, semi-cactus, and miscellaneous) and range from 1 to 6 feet tall. Winter-hardy only to USDA Zones 7-10; in colder regions the tubers are lifted in fall and stored frost-free, so most North American gardeners grow it as a summer annual.

The classic fall-flowering "garden mum" - a compact, clump-forming herbaceous perennial in the daisy family, grown for a prolific late-season flush of showy flowers from September to frost in shades of white, yellow, orange, bronze, purple, and red. A complex hybrid of five Chinese species, not native to North America; widely sold as a one-season annual but hardy in the ground roughly zones 5-9. Deer- and rabbit-resistant, and a welcome late-season nectar source when little else is blooming.