This cultivar has H. sieboldii in its background. It was registered by Peter Ruh of Ohio on behalf of the originator, Eric Smith of England in 2008. 'Emerald Isle' forms a small size mound about 10 inches high with a spread of 21 inches. The foliage is green with a white marginal variegation. Its leaves are moderately corrugated, slightly cupped and have thin substance. White flowers bloom in August.

According to The Hostapedia by Mark Zilis (2009), "This plant has been much debated, but rarely seen. The true plant has white-margined foliage and white flowers. It is not to be confused with 'Emerald Ruff Cut' ('Emerald Island'), a much larger plant with gold-centered, green-margined foliage."