Mine has slowly increased in very dry ground under trees and shrubs, seemingly thriving on almost total neglect; producing its red-flushed foliage each spring just after the masses of red-sepaled flowers.
This is a hybrid between E. alpinum and E. grandiflorum, forming spreading clumps up to sixteen inches (40.46 cm) tall.
Also fairly easy to obtain is E. alpinum, a semi-evergreen, draught tolerant species from southern Europe whose tiny, bright flowers are held below its medium size leaves. This is a valuable ground cover for dry shade, reaching twelve inches (30.48cm) tall and spreading about the same each year.
Darrell notes that in USDA zones 7 and warmer, leaflets on the true evergreen varieties will remain relatively intact throughout winter unless sited in very exposed spots. In colder zones, they may remain attractive through December. True deciduous species drop their leaves cleanly, where the evergreen ones hold on to them for dear life. Old leaves should be cut away in early spring before the flowers emerge, partly so you can see the flowers better and partly because if you wait until the flower stems and new leaflets unfold, you will have a very tedious time removing the older foliage. Darrell says that if the old foliage is still green, leaving it on the plant will encourage more robust leaves and flower scapes.
E. brevicornu is a very hardy, quite distinct deciduous species from northern China. It's hardy to at least USDA zone 4 and possibly 3.
It forms an eight to ten inch (20.32 - 25.4 cm) high mass of small, rather round, heart-shaped leaflets. New leaflets are mottled with reddish-purple and, when mature, are thin with the texture of parchment paper.
The lovely small flowers are born on ten inch (25.4 cm) long spikes.
Epimedium diphyllum
E. diphyllum is deciduous species native to S. Honshu, Shikoku and Kyushu, Japan. It's unique in possessing one or two pairs of small leaflets per leaf. Flowers are small, simple (without spurs) and, normally, white. Generally clump forming, they bloom later than most species, coming into bloom just as the typical E. grandiflorum are finishing. Darrell says they are said to dislike alkaline soils, though he does not know to what extent this is true. He also notes that he has a few clones with rhizomes that spread two to three inches per year (5 - 7 cm).
