Emperor I® Japanese maple (Acer palmatum 'Wolff') Genus:  Acer I’ll never forget when, in the mid-1990s, I called up a renowned nurseryman in Pennsylvania with questions about a holly, and he shifted the conversation to a new Japanese maple he had bred. “Emperor I®—better than ‘Bloodgood’,” he said. But we have all heard comments like that before. Plant breeders tend to borrow glory from classic plants by claiming their new version is better, but my skepticism about Emperor I® was quashed a year later when I acquired my first small tree. It’s a fast grower—unlike ‘Bloodgood’, which can take years to become a sizable tree. Also, unlike ‘Bloodgood’, Emperor I® holds its spectacular burgundy color all summer in full sun, and when fall rolls in, it evolves to a brilliant fiery red. Problems: 

Japanese maples are known for getting into trouble if late-spring frosts hit the emerging foliage. In my hometown of Louisville, Kentucky, in spring 2007, we had four nights when temperatures fell to 20°F to 25°F after our trees had completely leafed out. Luckily, the late leaf emergence of Emperor I® pro­tected it from the devastation that damaged and killed our other Japanese maples—including ‘Bloodgood’.

 

-Michael Hayman is the arborist for Seneca Gardens in Louisville, Kentucky.

Overview

Height 15 to 20 ft. Spread 15 to 20 ft. Growth Pace Slow Grower Light Full Sun to Part Shade Moisture Moist, well-drained soil Maintenance Low Characteristics Showy Foliage Foliage Color Colorful/Burgundy Foliage Type Trees