I have entire branches dying off. For the most part it seems like it is the entire branch dying and quickly. Most of the rest of the tree is fine. The were planted 5 years ago and seemed fine until last summer.
Can you post some photos? Best to get pics of the entire tree, and also close-ups of the base of the dead branches.
Hope these come out right. Here are two examples. I am so upset. I have five years invested in these.
It looks like the long dead side is due to exhaust from a vechicle. The thin bottoms are due to a combination of grass blocking light and the fact these cedars (most likely)originated from growers on the west coast and they take a while to acclimate to the east coast. Other spots don't know about. As for cure, you need to get rid of the grass and mulch the areas around the cedars, water on a regular basis and add some organic fertilizer once. As good organic mulch decompose it will add nutrients to the soil. It also pays to buy plants grown in your local area, they are acclimated to the conditions far better than plants grown in a more temperate climate.
There are no vehicles anywhere near these to cause damage from exhaust. What you might be seeing in the picture is my camper. My truck never gets any closer than 30' while I am hooking up so I can not imagine that would be the problem. The camper does not block sunlite to these either. The grass has grown in fairly close to the trunk. I will cut the grass back. How much area around the tree trunk is ideal? For a novice what exactly does the grass do in a negative way?? The Arbs are 5 years old and have always been automatically watered so I do not think it would be a watering or soil problem. Thanks for the help. Regards, Joe
The large dead branch, I'd check its base to see if anything (e.g. squirrel) has chewed the bark off all the way round the base of that branch. Could be the same for the smaller dead twigs too. That the rest of the foliage is healthy makes me think that a disease is unlikely. They are, as stated by the original poster, arborvitae (Thuja), not cedars (Cedrus)!
Dear NYcamper - Since this damage became apparent in the summer it could have been misplaced lawn fertilizer. If it was being broadcast mechanically parts of your trees may have got some drift. Nitrogen will burn foliage of evergreens and it is a large compnent of lawn fertilizer.
