Possibly a hybrid of H. rectifolia x H. ventricosa, this cultivar was registered in 1983 by Le Jardin de Botanique de Montreal, Canada. It forms a large size mound about 26 inches tall by 62 inches wide. The foliage is wavy, ovate, has smooth texture and better than average substance. Its medium lavender flowers bloom from late July into August on scapes that may reach 75 inches in height.

According to The Hostapedia by Mark Zilis (2009), "Try planting 'Tall Boy' alongside other cultivars with tall scapes, such as 'Canadian Foreign Affairs', 'Krossa Regal', and 'Sunami'."