call your county extension office ...

or google thru that nutty college in columbus ... they are one of the leading Ag colleges in the country ...

ken

Bordering on Ohio in 2011 (the latest map available), so I'd expect it's in now, but only just. And I'd suspect unlikely to be a major problem as Ohio's colder winters will keep it in check to a fair degree.

Resin

Here is a link that might be useful: HWA 2011 map

Ken & resin, thanks

HWA has officially jumped the Ohio River and has been found in Washington and Meigs counties. In surveys late this winter, a very small population was found in the Cantwell Cliffs area of Hocking County as well.

In addition to those probable natural spread locations, there have been a several finds in landscapes and garden centers over the last 10 years or so, most all as a result of infested nursery stock coming in to the state. Virtually all of those have been eradicated, but it is certainly possible that there is another pocket or 2 out there, as yet undiscovered, in Ohio.

As pineresin mentioned the colder climate does seem to keep them in check in northern Ohio. I am aware of one find in a back yard in the Cleveland area last year. Those 4 trees had been planted 12 years earlier, and were finally noticed by the homeowner. They were substantially infested but not dead, and the pest had not spread to rest of the neighborhood, and there were many hemlocks in the residential neighborhood.

So yes, HWA is in Ohio, but mostly in isolated pockets, far from the Canton area. Based on what we have seen so far, I am not afraid to keep planting hemlocks here in my part of northern Ohio.

Here is a link that might be useful: HWA in Ohio

I wrote to OSUE. I think the tipping point for them in my note was that next year I intend to get a beehive and that spraying the trees if they got HWA, would be out of the question. They said they could not recommend me planting hemlocks.

FWIW, to anyone else reading the post, Merit/imidacloprid seems so effective at treating that my trees are still free it of about 3 years after I applied it for 2 years in a row. I presume the adelgids were all killed off and it will become reinnoculated at some point; but hemlocks are becoming rare in suburbia, I think the only other ones in my 'hood were cut down last year. (might have been combined Hurricane Sandy + disease state that finished them off) Do they use anything else as an alternate host?

Yes, I know there are concerns about what that chemical could be doing to pollinating insects, and I'd rather not use it. Obviously they don't suck hemlock "nectar" but a small amt. of what is applied as a root zone drench might get into some nearby rhodies. I only applied the drench right around the trunk, though. I'm planting to replace the shade my hemlocks give but obviously that is going to take a while. I only mention this for people like me who are in the position of _having_ to maintain trees. I had very, very little high shade and a strong interest in collecting woodland plants, so my hands were tied.

This post was edited by davidrt28 on Wed, May 22, 13 at 9:58

Buckeye:
With winters seeming to become milder I would not count on HWA staying in the southern most portions of Ohio. Not to mention the fact that many pests of any type - fungal, animal, insect, plant - have spread beyond their expected ranges; pesky little thing called evoluation at work. Finally, some of the areas depicted in that recent range map are just as cold as Canton.

If I were anywhere that HWA was a remote possibility, I'd only plant one of the resistant Asian species.

This post was edited by davidrt28 on Wed, May 22, 13 at 9:59

The woolly adelgid has swept thru this region but have declined or temporarily disappeared. Some small understory hemlocks (30' tall) nearby had been infected, but recovered nicely. But 70 miles to the east on the Blue Ridge (MD) death of hemlocks was near 100%, so their future is unknown.

IMO, in Canton OH, go ahead & plant some, but not many, knowing you could lose them.

Im originally from NE Ohio and at my parents property in the Cleveland area there have never been any problems with hemlocks. They are a beautiful, graceful evergreen and despite the warmer winters (it really hasnt gotten below 0F/-18C) for three years in the area we have seen no sign of it. I would risk it just for the beauty.

Thanks for that information beng. I do remember hearing that about some areas that had infested trees that then seemed to get better on their own. Was there any theories as to why? Maybe the release of some of the beneficial insects from the HWA native range?

I haven't given up on stopping this insect in Ohio. The thought of Hocking Hills and Mohican without hemlock is too much to bear.

For what it is worth, Tsuga diversifolia (a resistant species) is performing beautifully here in northern Ohio.

Buckeye15, thank you for the alternative suggestion. I think I will go with that.

buckeye15, they have been releasing some kind of adelgid predator, but not sure if that's the reason, or climate, or something else.

The release of a Gypsy moth parasitic fungus took a couple decades to get going & eventually decimated the moths.