Blue hosta

Farfugium japonicum is an evergreen rhizomatous perennial native to streamsides and rocky seashores of Japan, Korea, Taiwan, and coastal China, where it is known as tsuwabuki (石蘗). In gardens it delivers bold, kidney-shaped leaves up to 10 inches across and cheerful yellow daisy flowers in autumn and winter - a genuinely useful combination for dark, damp corners. The honest catch is toxicity: the plant contains petasitenine, a carcinogenic pyrrolizidine alkaloid; it must be kept out of reach of children and pets and handled with care, and it is frost-tender above USDA zone 7b, dying back or suffering severe leaf scorch in hard freezes.

An exquisite, delicate spring bulb grown for its solitary, nodding, bell-shaped flowers, which are uniquely chequered in a chessboard pattern of purple and dusky pink (or, on white forms, a faint ghost of the same lattice) and held on slender stems over fine grey-green leaves. The pendent, snake's-head bells give it both its common name and its quiet, wild charm. Native across much of Europe (POWO, Kew), it is a treasured but much-declined wildflower of old damp meadows, and its decline is a real conservation concern, which makes it a genuinely good plant for naturalizing in moist grass to help restore a lost habitat. Two things are load-bearing: unlike most spring bulbs it wants soil that stays moist, even damp, and does not dry out, so it fails in hot, dry spots; and it is toxic if eaten, since the bulb and all parts contain alkaloids. It is also a valuable early nectar source for the first bumblebees of the year. Hardy across USDA zones 3a-8b, it carries the RHS Award of Garden Merit and is rated fully hardy (H5).

Hakonechloa macra is a slow-growing, clump-forming deciduous grass endemic to Japan, naturally found on rocky woodland slopes near Mount Hakone and across Honshu. It is prized in shaded gardens for its gracefully cascading, fountain-like mounds of thin, arching leaves and warm autumn tones of red and pink. The honest catch is pace and site sensitivity: it is among the slowest ornamental grasses to establish, struggles badly in hot dry summers without consistent moisture, and is prone to leaf scorch if sited in too much sun - it needs rich, reliably moist soil to earn its reputation.

Persian buttercup is a tuberous herbaceous perennial native to the eastern Mediterranean - from Cyprus, Crete, and Turkey across to Iran, Iraq, and the Levant - where it blooms in rocky scrub and meadows in late winter through spring. In gardens it is prized for its luminous, poppy-like flowers in red, orange, pink, yellow, and white (wild single forms) or the dense, multi-layered doubles of commercial 'Tecolote' and 'Bloomingdale' strains beloved by florists. The honest catch is its frost-tenderness: the tubers are killed below roughly 14°F, so gardeners in USDA zones 7 and colder must lift and store them after foliage dies down each summer, and the whole plant contains protoanemonin, a skin and gut irritant toxic to humans and livestock on contact or ingestion.

Gentiana acaulis is a low, mat-forming alpine perennial native to the mountains of central and southern Europe - the Alps, Pyrenees, and Balkans - where it grows in short turf and rocky meadows from 2,625 to 9,843 feet elevation. In gardens it is prized for its astonishing, deep-blue trumpet flowers in late spring, and it has received the RHS Award of Garden Merit. The honest catch is its notorious habit of "sulking": well-established plants can refuse to flower for years with no apparent cause, and the gardener's only remedy is to dig and replant the mat a few inches away - a maddening behaviour that makes it a reliable showpiece in some gardens and a frustrating non-bloomer in others.

A warm-season native bunchgrass of the eastern and central United States, also called hairawn muhly or purple muhly, grown for the airy clouds of pink to pinkish-red flower heads that float above its fine, wiry leaves from September to November. It takes heat, humidity, drought, salt and poor sandy or rocky soil, is highly deer resistant and needs little care beyond cutting back in spring. It is rare, known only from old records or gone from much of the northern edge of its wild range, so buy nursery-grown plants rather than digging wild ones.