Borers?

Borers with info provided.

Dan

Thanks and they would kill the top of the tree? How do you treat against them?

Birches are short lived precisely because they're borer bait. There are some ugly systemic pesticide treatments for borers, but it's a continual and, in the end, typically losing battle. Nothing is going to make the top of your tree recover. Cut it down. If you must have a birch (and, yes, they're lovely trees), then plant a river birch which, unlike it's cousins, isn't borer bait.

I sure hope you haven't given up on your birches yet! Many birches and aspens are susceptible to borers, which may be causing the trunk damage you describe. Unlike some other gardeners, I'm not inclined to dispose of a tree because it has borers, and thanks to my local (northern colorado)extension office and expertise, have had tremendous success using beneficial nematodes to control borers. I live in Zone 5, Colorado, and applied them to my trees in liquid form when there was a severe infestation of borers three years ago. Beneficial nematodes are not harmful to the environment or humans and are being increasingly used to control pests like borers very effectively. Three years ago, the treatment also saved three of my mature aspens (10" diameter trunks). I'm not predisposed to cutting down a tree at the first sign of borer now that I've had such great success. They're inexpensive, effective, easy to apply. What more could a gardener ask for? Beneficial nematodes can be easily obtained from a number of manufacturers and are live microscopic creatures that are naturally predatory parasites to borers. Borer infestations are easily controlled using beneficial nematodes in one season in my experience. They are sensitive to freezing (but you can refrigerate until you can use them),high temps, and ultraviolet light, so should be applied by early summer at dawn or dusk to trunks and roots, and watered in well (or later at higher altitudes). One can buy them cheaply and apply them in liquid spray form with a standard yard hand sprayer. I happen to even have used my Miracle Gro sprayer. I swear by these lovely (microscopic) creatures, as they saved my beautiful trees! I don't know about the rest of folks, but as a gardener I'm more inclined to save try to my trees than destroy them whenever possible, and particularly in this economy, to preserve the value of my property that mature trees bring--not to mention the value and pleasure they bring to me in their beauty. Below is a link you might find helpful and/or you might try your local ag/extension office. Good luck!

Here is a link that might be useful: Beneficial nematodes

PS - sorry forgot to say also that I also obtained got a simple plant syringe at my local nursery for about a dollar, and in addition to spraying, "injected" the nematode solution into as many borer holes as I could reach on the trunk the same morning I sprayed the solution on the tree trunks and roots... Like I said, the whole process was extremely effective for very little cost and effort.

many opinions...

the one thing i didnt see .. is where the tree is located..

if it threatens.. you.. the neighbors.. the house.. the garage..

then it simply has to go ... whats the use of saving something that is a threat ...

also ... whether or not the treatments will rid the tree of the insects ... if in fact that is your problem ... you will be left with a tree that will need proper pruning ...

when it all boils down ... it might be worthwhile to divest in this one.. and replace it.. for less than the combined costs of saving it ...

the opinion of a certified local arborist is probably the best suggestion.. though even that cost might not be worth investing

ken

I don't cut down trees at the first sign of borers either, but the OP is obviously well past the first sign of borers. Big sections of his tree are dead. Neither nematodes nor imidacloprid are gonna fix that.

Cut it down. Plant a borer resistant tree -- or learn to identify "the first sign of borers."