Hello, I have two 10′ lines of Green giant arborvitaes in my back yard, all of them have here and there yellow spots of dead or dying needles. This started in the spring. Please advise if it can be some disease or pest problem and how to resolve it. I did some inspection with a magnifying glass but could not find anything.
Thank you for contacting the Toronto Master Gardeners.
We receive numerous questions concerning yellowing cedars. I’m attaching a link to a previous questions & answer which should give you some guidance-also Search on the website ’emerald cedars’ and other information will be listed, see below: