Giant onion

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).

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.

Amaryllis belladonna, the belladonna lily (also Jersey lily, naked-lady, or March lily), is a bulbous perennial geophyte from the Western Cape of South Africa. It is grown for its dramatic autumn display: leafless stems carry umbels of 6-12 fragrant, funnel-shaped pink to rose flowers that appear before the strap-shaped leaves emerge (a hysteranthous "naked lady" habit). It suits the front-to-mid border, gravel and Mediterranean-style plantings, and large containers in a hot, sheltered, sun-baked spot. Be plain about two cautions: the bulb is only modestly frost-hardy (roughly USDA 8/9-11; RHS H4) and is best given the warmest, driest position available in cooler areas, and ALL parts of the plant are TOXIC, containing lycorine and related Amaryllidaceae alkaloids that cause vomiting and diarrhea if eaten by people or pets. It also naturalizes readily in mild Mediterranean climates, so site it where self-sown spread is welcome.

A long-lived native perennial of central and eastern US woodland borders and prairie meadows with deep blue pea-shaped flowers in late spring, blue-green leguminous foliage, attractive black seed pods for winter interest, and a nitrogen-fixing root system (Fabaceae). Larval host for 6 documented butterfly species per NC State (orange sulphur, clouded sulphur, frosted elfin, eastern tailed-blue, hoary edge, wild indigo duskywing) - among the highest Lep-host-count perennials in the eastern flora.

An architectural, branching perennial grown for the metallic steel-blue flush it takes on in summer: small, egg-shaped flowerheads, each ringed by a collar of spiny, silvery-blue bracts, are held on rigid, blue-tinted stems above a basal rosette of leathery, heart-shaped leaves. It is a tough, genuinely drought-tolerant plant for hot, dry, sharply drained, even poor sandy or gravelly soil in full sun - it resents rich, wet ground, where it rots and flops - which makes it ideal for gravel gardens and coastal, seaside plantings, and one of the best long-lasting cut and dried flowers. At the height of summer it is a magnet for bees, butterflies, and hoverflies. It is grown purely as an ornamental and is not eaten.

The hardiest of the nerines and a classic late-season border bulb. In autumn it throws up bare stems topped with bold umbels of glistening, wavy-petalled, bright-pink trumpet flowers - opening before or with the strap-shaped leaves - to light up the garden when most bulbs are long finished. Native to the summer-rainfall Drakensberg uplands of South Africa, its montane origin gives it the cold-hardiness that sets it apart from the tender Cape nerines: it survives outdoors in much of the UK and to about USDA zone 7b in a warm, sunny, sharply-drained spot. The bulbs are toxic. The single most important fact to get right is its upside-down season: it flowers in autumn, leafs through winter, and rests in summer - so it is watered through autumn and spring and kept dry at rest, never the other way around.