When many trees of the same species are grown in an urban landscape, they are frequently attacked by a variety of pests and diseases. These problems are often exacerbated because of the high density ...

Every now and then a tree problem suddenly emerges that result in dozens of calls and e-mails. The tree in question is Mancana ash - a variety of Manchurian ash. I wrote about problems with this tree ...

The tiny emerald ash borer is doggedly chomping through the Greater Toronto Area's ash population, turning once leafy trees into ghostly wooden skeletons. The infestation of the invasive, wood-boring ...

Toronto's "urban canopy" is under threat, with as many as 860,000 of the city's ash trees projected to die within the next four years unless they're treated this summer against the scourge of a green ...