Hemlock blight

[hoss]

Could someone tell me what it is that is killing hemlocks in the virginia pennsylvania area(maybe elswhere?)? I am going to be dropping 6-8 large ones(30-50") for my father-in-law and I need to know if what's killing them will also ruin their lumber potential. Thank you for any help.

 

[darkstar]

I saw hemlocks dieing here in tennessee but i could never find any sign of this insect. The hemlocks around here that are dieing turn yellow but only in very patchy areas through the tree.The yellowing then quickly turns brown and soon the entire tree dies suddenly .

 

[moss]

I saw hemlocks dieing here in tennessee but i could never find any sign of this insect. The hemlocks around here that are dieing turn yellow but only in very patchy areas through the tree.The yellowing then quickly turns brown and soon the entire tree dies suddenly .

By the time the hemlock is turning yellow and patchy there may not be many or any adelgids left on the tree. The adelgids don't directly kill the tree. They suck nutrients and gradually weaken it over several years. The tree basically starves, becomes vulnerable to disease and drought, continues weakening and then dies when it doesn't have enough foliage left to make food.