cedar tree death

[thedeeredude]

At work we have some what I believe to be white cedars.  On a couple of the trees more than half the needles are brown and on most of the trees theres a fair amount of brown needles.  What could it be and how do we fix it?  Thanks.

[Ron Wenrich]

Bagworms can hang a number on arborvitae.  Look to see if there are any old cocoons on the tree.  They will look similar to a pine cone, but, if you look at them real close, you'll see that it is made from arborvitae needles. 

I have had them in the past.  They get on ornamentals and the native red cedar.  They don't have much effect on the red cedar, but they will cause a lot of brown out and later death on the ornamentals.

There are 2 controls.  One is for spraying, and the other is for picking them off.  I picked them off when they were active - June and July.  I haven't had an outbreak since.  Mine were smaller trees, about 10-12 feet high.

Once an area is dead, its gone.  I have seen them put pretty big holes on some trees where the owners didn't know what it was.

[SwampDonkey]

Any pictures?

You will get some degree of dieback in white cedar every year as a natural process. Really old cedar have a sparse crown, often a 15 foot limb with leaves near the last 3 feet. Also, in my area the foliage turns a bronze color over winter months.

You have any pictures? 

Never noticed the bagworms, but Ron may be onto something.

[TexasTimbers]

Bagworms got the two cedars in front of our house around June I believe. I didn't know what to do but my dad said to mix a 50% solution of Dawn and water and douse the trees liberally. About a week had passed before I knew what was going, got the advice, and got them sprayed. It killed the bagworms allright but ti also burned what little green was left.
The solution made the worms come out starting almost immediately. Now, the empty bags are still there but the evergreen is coming back with little clusters of green springing up all over the trees.
I would have swore they were beyond revivial I mean they looked dead and dry as a bone.

[Brian Beauchamp]

What's been going on around the trees? Have people been parking under or around them? Soil compaction, additional soil or rock over the rooting zone will reduce soil oxygen and cause respiration problems for the tree...which may result in DEATH! 

...for the tree, that is

[thedeeredude]

No, these trees are up on the hill in a small cluster,  nobody messes with them.  I didnt check out for bagworms, didnt see anything but didnt look real close either.  And we cant spray anything on any vegetation, its an institution and special permits are needed, but we dont have(ie, want to spend) the money to hire someone   The trees arent terrbily tall.  I can try and get some pictures next week.  Monday be a holiday