He first saw the disease in a red obelisk beech in Jamestown in 2021. Now, he’s treating more than 300 sickened trees at estates in Newport, Narragansett and the Watch Hill area of Westerly.

Ornamental beech trees are available in various colours, but the most outstanding is deep red. Dawyck Purple and Red Obelisk are most widely used, both eventually growing over 10 metres high and ...