Immunity to Emerald Ash Borer

Mountain Ash berries
Mountain Ash berries

The threat of Emerald Ash Borer to our native and urban forests has been in the news a great deal in recent years, and the threat is real and growing.  Only time will tell how devastating Emerald Ash Borers will become, and if efforts to control this destructive insect will help at least to some degree.

While the list of counties with infestations of Emerald Ash Borer has been gradually growing (not yet found in Rice County, but verified in Dakota County), we are able to sell a lovely tree that carries the ash name, and is resistant to the Emerald Ash Borer.  Our Minnesota native Showy Mountain Ash produces beautiful white flowers in late spring and by late summer, displays loads of colorful, orange/red berry clusters that are long lasting, and a favored food for a number of wild bird varieties.

The catch here is that Showy Mountain Ash is immune to the Emerald Ash Borer because it is a member of a completely different genus of trees than the Green Ash, White Ash or Black Ash currently being killed by the Emerald Ash Borer.  Showy Mountain Ash belongs to the genus ‘Sorbus’, while the White, Green and Black Ash trees are part of the ‘Fraxnus’ genus of trees.  Emerald Ash Borers do not attack the Showy Mountain Ash trees.

Showy Mountain Ash trees grow to modest heights of 20′-30′ in most cases which makes them an excellent choice for smaller spaces when a full sized shade tree might be too big.  For best results plant the Showy Mountain Ash tree in well-drained soil, and avoid compacted, poorly drained areas.  Showy Mountain Ash prefer 1/2 day to full day sun.  The colorful clusters of orange berries decorate the tree throughout the winter, or until they are eaten by hungry birds.  Showy Mountain Ash have become one of my favorite Minnesota native trees.