Epimedium x versicolor ‘Sulphureum’ – Commonly known as Barrenwort or Bishop’s Hat, this semi-evergreen perennial bears primrose yellow flowers from mid to late spring. The heart-shaped leaflets emerge with a distinct reddish-bronze tinge, maturing to green. This Award of Garden Merit winner is drought tolerant once established. Grows 12-15″ high. Zone 5.
Meconopsis betonicifolia (recently reclassified as M. baileyi) – The Tibetan Blue Poppy is a much coveted but difficult to grow perennial. Discovered in 1912, it bears 3-4″ wide translucent sky-blue blooms in early summer. It is herbaceous and short-lived, preferring part sun and even soil moisture during summer. Grows 24-36″ high by 12-18″ wide. Hardy to zone 3.
Polygonatum x hybridum – The Common Solomon’s Seal is a cross of P. multiflorum and P. odoratum. It bears clusters (usually 4) of creamy-white flowers with green tips, trailing below the arching stems. The green lance-shaped leaves are borne alternately on the stem, turning a beautiful yellow in the fall. Grows up to 5′ tall and spreads by rhizomes. Zone 4.
Brunnera macrophylla ‘Looking Glass’ – This heavily variegated Siberian Bugloss is a sport of ‘Jack Frost’. It produces almost completely silver leaves at maturity (in 1 or 2 years) that nicely compliment the bright blue forget-me-not flowers (with yellow centers) that show from April to May. ‘Looking Glass’ is best in light shade. Grows 12-16″ high by 12-24″ wide. Zone 3.
Disporum flavum (syn. Disporum flavens, Disporum sessile var. flavens) – The Korean Fairy Bells bears clear yellow blooms (in clusters of 1-3) in spring, followed by black berries in early autumn. This clump-forming perennial is somewhat similar to Solomon’s Seal in its growth habit with its elegant arching stems. Grows 18-30″ high by 12-15″ wide. Hardy to zone 4.