English bluebell

A low, clump-forming native woodland violet of eastern North America, grown for its early spring blue-to-purple flowers with conspicuous white throats held over glossy, heart-shaped leaves. It does not run, but self-seeds freely - to the point of being weedy in rich, moist ground. A larval host for fritillary butterflies and a nectar source for early bees and butterflies; the leaves are high in vitamins A and C.

Common lungwort is a low-growing, rhizomatous herbaceous perennial native to deciduous and beech-mixed woodlands of central and western Europe, from Belgium and the Netherlands east to the Caucasus (Wikipedia). Its white-spotted, heart-shaped leaves and early-spring flowers - opening pink then aging to blue-purple as petal pH shifts - make it one of the first-blooming shade groundcovers in the garden. It thrives beneath deciduous trees in humus-rich, consistently moist soil and is reliably hardy through zone 3. The honest catch: in heat, drought, or poor air circulation it collapses into disfiguring powdery mildew mid-summer, often leaving the foliage blackened and unsightly until new basal growth re-emerges - siting in cool, evenly moist shade with good airflow is not optional.

Chinese astilbe is a clump-forming herbaceous perennial whose wild range Wikipedia gives as eastern China, the Japanese archipelago, and Korea (with Manchuria and the Amur basin in broader botanical-country treatments), growing along shaded streams and in damp broadleaf-forest margins at elevations of 1,312 to 11,811 feet. In the garden it is prized for feathery, upright plumes in mauve, rose, or purple over ferny, deep-green compound foliage in summer, and is one of the more reliable performers in the part-shade border. The honest catch is moisture: despite being the most drought-tolerant species in the genus, it still demands consistently moist soil and will scorch and collapse quickly in hot, dry exposure, so plant it where soil never dries out and expect little in dry shade under thirsty tree roots.

A dry-country wildflower of the Intermountain West whose narrow, scarlet, tubular flowers line a slender stalk that rises about 3 feet above a low rosette of glaucous blue-green leaves. The Lady Bird Johnson Wildflower Center documents it blooming red from May into August on dry, gravelly soils, and it is one of the classic hummingbird-pollinated penstemons. Deeply drought-tolerant once established - best on lean, well-drained ground where it is not over-watered.

Great masterwort is a clump-forming herbaceous perennial native to the mountain meadows, grasslands, and forest clearings of central and southern Europe (the Pyrenees, Carpathians, and Balkans) and east through the Caucasus to Anatolia (Wikipedia). Its distinctive pincushion flowerheads - a dome of tiny florets ringed by papery star-shaped bracts - bloom from June through September in white, pink, and deep red tones, making it a long-season cottage-garden favorite. It performs beautifully in cool, evenly moist sites with partial shade. The honest catch: Astrantia is a cool-climate specialist that sulks badly in hot, humid summers - in zones 7b and warmer with heat-laden summers it loses vigor, fades early, and is prone to powdery mildew; consistent moisture is non-negotiable and drought even for a week can trigger early summer dormancy.

A clump-forming aromatic native perennial of eastern North America, grown as much for its silvery floral bracts as its bloom - the upper leaves below each flower head turn a frosted, dusty-mint color in summer. Dense flat-topped clusters of tiny two-lipped pinkish-white flowers cover the plant from mid to late summer and are a magnet for bees and butterflies. Unlike the true mints (Mentha), it spreads only modestly by rhizome and is not invasive.