Hemlocks Are Dieing

[darkstar]

here in chattanooga the hemlocks are turning yellow ...very spoty ...many trees look green and great but have irregular yellow patches ... ive never seen this befor but it seems wide spread at higher elavations ... and now ive seen several slowly lose their needls and die all together i havent located any insect or eggs and cannot see any apparent fungus .... the yellowing is very irregular just a limb here or there and many .... ill try and post a pic ... a landscaper told we all of them are dieing .... ive been to busy with removals to take notice ...anyone know what happening ....it seems widespread .....dark

 

[kennertree]

Yep, i'm a few hours north of you dark, right around knoxville. Alot of the hemlocks around here are dying from the hemlock woolly adelgid. It is real bad in the smokey mountains. If its caught early, the bug can be killed and the tree will survive.

 

[darkstar]

how can i identfy this bug ... i searched many hemlocks extensivly today actuallt took hours i found no eggs nothing ... can someone reccomend treatment once i have correctly diagnosed ... this is really bad ... and widespread anyreplies helpful thanx dark

 

[kennertree]

They are really hard to see, from the trees ive seen they lay eggs on the ends of branches. It reminds me of that fake snow you spray on a christmas tree. If left uncontrolled it can kill the tree in 4 to 10 years. There are 2 approved methods that have been proven effective and can be done by the homeowner. These are just a few available for homeowners, of course there are other methods that an arborist will have to apply. One is bayer advanced garden tree and shrub insect control. Its mixed with water and and poured around the base of the tree. The most effective time is in the spring when the sap is rising. One application per year will usally take care of it. The other is an insecticidal soap. To be effective the tree needs to be completely drenched above and beneath all branches.

 

[apparbor]

Okay, here goes. The yellowing of the needles in areas you see is probably normal. Hemlocks shed needles every Spring and Fall and that is the way it appears. It can be heavier from time to time.
I am in Asheville, NC and we have been dealing with Hemlock Wooley Adelgid (HWA) for awhile now. Do a search on the internet and you'll find a photo of it. The long and the short of it is that you would see the eggs forming in the Spring and the Fall. They are found at the base of the needles along the twig and look like tufts of cotton. Yes the crawlers are pretty tough to see. The eggs are easy to spot. I don't know if you have HWA in your area yet, but I do know it is in the Smokies, Western NC, North GA and further North. There are other pests of Hemlocks as well.
My company is currently working with the Park Service treating for HWA and doing research. You should find treatment info on the internet as well. I would discourage the use of soaps or sprays in general. Soil injection works very well and is my preference, we use Zenith ( a cheaper version of Merit ). If it is near water we use trunk injections of Imicide, which is a Mauget product.
If treating you should not treat every year (merit soil treatments). If you read the label you will find that Merit will have a residual of ~18 months. I have seen it last as long as 3 years. When treating trees for pests you should always do some monitoring, never go on automatic.
I hope that's clear as mud! If I can help with info let me know.