One of my business hats is being a Certified Arborist working on golf courses in the Greater Toronto Area. Right now the biggest threat to golf course trees is Emerald Ash Borer. A local club I've been working with has an Ash population of 25%, and others range between 10-15% so if this pest arrives, there will be a substantial impact to the aesthetics, and playability of the golf course. The product I used to treat some Ash trees, TreeAzin, is mentioned in the video below. The active ingredient is a product of the Neem Tree, and so far there have been good results showing the effectiveness of this product against Emerald Ash Borer. Check out this video about the Town of Oakville's aggressive action to treat Ash Trees.
Darryl James - Arborturf Solutions