I wouldn't remove them. Tho many were killed early on, many now hang on w/damage, but not enough to kill them (one at my brother's house for example). The adelgid population, at least here at present, cycles between alot of them or nearly none. Not sure why -- perhaps something has been attacking them.

I could not get rid of the 'wooly' or the deer - I removed them in 2024.

Dead branches can be removed. How big are your Tsugas?

tj

about 30 feet. Mostly, it's the lowest branches that have the pest issue. Why? BTW, Japanese Lantern Flies are also BIG around here this year. Surprised as last year they were not around. Don't get these waves of pests.

41, not sure, other than the adelgids aren't good fliers, so tend to occur lower down. I think alot of their distribution comes from wind too.

This article has information on adelgids that I never knew before (a lot that I knew too).

https://www.caryinstitute.org/news-insights/feature/7-facts-about-hemlock-woolly-adelgid

Thanks, I read it, depressing. Sounds like the species is on the way out in my area. Not cold enough now to kill the pests.

Some sources feel that where the tsuga beetles have been released, there are signs of a lessening of damage from the adelgids. We can only hope.

Haven't seen any up here so far but then we're still getting -20's near -30 here last winter.

One encouragement is that areas near me, like the Rocky Gap Md state park, have hillsides where there are hundreds of seedling hemlocks in the understory. Unlike many tree seedling species in the understory, they will persist in the shade.

I was surprised to see that it only took -10F to kill most of the critters.

A lot of more northerly areas experience that kind of cold not infrequently.

Anything that slows them down will help. At least keep the trees from extinction.

I still have two small specimens.

You can tell which side gets the most sun (gets a few hours of full, beaming sun in the afternoon).

Another: Might have to protect this one, one more season, from sunburn this winter/spring.

I dunno Bill, brother's 25 x 20 ft hemlock got -10F this past winter -- didn't bother the adelgids, tho I can't see any general degradation of the foliage visually. There are many hemlocks on the way driving up that do show general foliage degradation and side branch death working upward, tho I think they've looked like that since the initial infestation 20 or so yrs ago.

I am leaving them right now, it is mostly the lower branches and wanna garden under the Hemlocks anyway, mid and upper layers of trees look good. P.S., my extended minimum temp over winters averaged is, 0-10 F so big cold is not going to help.

A couple years ago we drove the Blue Ridge Parkway east of Asheville and couldn’t help but notice the dead Hemlocks. It seemed devastating to me, but that isn’t meant to be definitive. Might the upper midwest become the locale for North American Hemlocks?

I've thought about trying one of the oriental (Chinese and Japanese) hemlocks because they are supposedly resistant to the adelgids, but searching didn't bring up any sources, and studying suggested they weren't the majestic tree-size hemlocks like the N American ones.

I read something about a bug (insect?) native to Japan that helps keep the adelgids down (that we don't have).

Another article stated the PNW has a critter that's been the reason they haven't had the widespread damage as they've had ''out east'.

Any adelgid in their right might wouldn't try to live this far north so I don't think I'll have any concerns about it. -27f was our coldest last January with some minus teens in the mix.

Here's the article about silver flies in the PNW (among other predators of the HWA).

https://entomologytoday.org/2015/06/18/west-coast-flies-to-the-rescue-of-east-coast-hemlock

Thanks, Bill. From the same site, an article about the imported fungus that, at least in many areas like mine, have pretty much destroyed the gypsy moths.

https://entomologytoday.org/2021/08/10/fungus-biological-control-invasive-moth-lymantria-dispar-entomophaga-maimaiga/

"Any adelgid in their right might wouldn't try to live this far north so I don't think I'll have any concerns about it. -27f was our coldest last January with some minus teens in the mix." Bill that keeps ME outta your neck of the woods too! OMG! You people are hardy! My recent average minimum is 5-10 F. above and I hardly survive.

I am keeping my island planting of them. Had landscapers remove the noxious weed wines growing up their trunks, used to be English Ivy, I ripped all that garbage out and had porcelain vine taking over. They don't really look too bad, just a few lower branches and I am pruning those. I do not use pesticides by general practice..., too much wildlife around. Adelgid are nothing this year, compared to the dreaded Japanese lantern monsters!!! Do you have them your way YET?! We had them a few years ago, then very few last year, now this year, it's an invasion! EVERYWHERE!!!! You literally cannot sit outside without them on you. And, they get BIG.

P.S. Just checked it out, Japanese lantern fly eggs do do not survive below 12-15 F winters..., LUCKY YOU!!!!!

Yeah, it's a trade off. Smaller variety of plants survive here AND a smaller variety of pests.

No poisonous snakes, scorpions or brown recluse spiders.

But there are some drawbacks, I just can't think of what they are right now. ;-)

Good luck with your Hemlocks.

Whatever Maryland released back in the 2000s seems to have helped.* I haven't seen adelgids on hemlocks around here in years. In fact I just got rid of a 10' seedling in my garden because I no longer wanted it...as with Henry Mitchell, they've never been my favorite conifer. And I really only have room for plants I consider my favorites! I thought of asking anyone in my 'hood if they wanted it, but, I'm getting more and more cynical about people and such gestures seem like more trouble than they're worth! It would have taken just a couple minutes to dig it out with my backhoe. Anyhow, it had absolutely no woolies on it...whereas the big hemlocks that spawned it were full of them by 2008 or so; I treated with neonics and they never had a problem again. They've been cut down now. They were casting way too much shade for such a dull tree bwahaha.

* according to Raymond's pics, the biocontrol hasn't reach SE PA yet, or for some reason isn't able to thrive there.

I spot enough hemlock here and there in Cecil and Harford county to make me think it's not a problem here anymore. This article doesn't mention it: https://news.maryland.gov/mda/press-release/2024/12/19/maryland-reaches-new-milestone-in-biocontrol-efforts-for-eastern-hemlock-conservation/

but I'm sure I read back then (2000s) that they also released those beetles near the hemlock forests of Harford County.

That is scary, I had no idea. Even when my 2 big hemlocks were full of them, I never saw them in my 2 large Norway Spruces.

David, the spot I mentioned had hundreds of huge, mature hemlocks -- all infested. So that was indeed a super-intense infestation. But the neighborhood "friend" I mentioned in the Douglas fir post also had an adjacent lot w/a heavily-infested row of young hemlocks where a few adelgids showed up on his nearby Douglas fir! But I've read that those conifers other than hemlock were not their desired hosts.

To add, David, if you crush hemlock foliage, you'll find it has a very fruity and pleasant fragrance.

I’m tardy with this, but as a Tsuga lover (junkie is already taken), it needs to be addressed.

”In fact I just got rid of a 10' seedling in my garden because I no longer wanted it...as with Henry Mitchell, they've never been my favorite conifer.”

David, you and Mr. Mitchell might be the only two people who dislike our native Hemlock. What is it that you dislike? The graceful habit? I hope you’ll explain your position in more detail.

As for Henry Mitchell, I had no idea who he is/was. For those who are also unaware, you can read about him here.

Ha! I didn't mean to touch any nerves!!!

I gotta admit, familiarity breeds contempt it seems. The only conifers in my growing up yard were: CBS (hated them for the prickliness, and of course now hate them because they all get diseased and look like crap) and eastern hemlock. So I guess I just associate them with boring suburban landscaping! Mind you I don't have active disdain for them that I do for various other things, like silver and red maples. (which I must have spent over 15K dealing with on my property) I just wouldn't say they're my favorite. But some people can take that as an insult...including me. The one time I cooked breakfast for my nephews and niece I'll never forget the stinging verdict one of the nephews gave of my pancakes: "not my favorite" haha.

If I had the resources to be making a 10 acre arboretum, I might have a grove of hemlocks. As it is, I just have to make space for things I do consider my favorites.

I began to admire hemlocks when living in a mostly-oak forest in southwest VA, and trekking downslope a long way in winter, came upon, among rhododendrons, a stunningly tall & dark green hemlock w/foliage way down low. Such a sight in an otherwise leafless forest. Also there was a forest of virgin hemlocks at nearby Mountain Lake Resort Virginia (4000 ft elev) that had very large ones estimated at 300 to 500 yrs old, the oldest had broken tops but soldiered on. Unfortunately, Hurricane Hugo's center moved right over there in Sept 1989 and destroyed all the biggest hemlocks. Some info on Mountain Lake below. You can actually see a couple remaining large hemlocks in the distance on the top pic.

https://cardinalnews.org/2022/12/05/geologists-still-plumbing-the-secrets-of-mountain-lake-and-its-mysterious-fluctuations/

I can remember only 10-12 years ago, when I first lived here, doing a lot of research on what trees to plant, in my then new garden/yard in town.

The DNR site listed Hemlock as native to MN, and I can remember thinking 'what is this strange tree? That I never heard of before'. lol

Being it was so different and obscure, I was fascinated with it and read, read, read all could about it, finally finding a specimen of one at a BBS one summer.

maackia,

I might be wrong, but we'll let davidrt correct me on this.

I think eastern hemlock are just too common for him and if he could grow some without them interfering with any of the more exotic species of plants that he likes to grow and if he had 3 times the garden size he has now, then you might see a planting of Tsuga there. ;-)

Come at me bro! ;o)

Wow, I got in a lot of trouble just for saying something 'wasn't my favorite'.

Yes, the point of my gardening has always been to grow what is different. Why? For one thing, I think unlike most young Americans, I worked for several neighbors/people in my town who had impressive albeit traditional gardens. So I was already thinking about gardens well before most people would. So although I admired and respect such gardens, by the time I could start making my own place in my late 20s, I thought, 'why just duplicate what's been done before'? There are hundreds of other suburban yards where you can see eastern hemlocks planted. My yard might be one of about 10 private gardens on the east coast where you can see an Abies pindrow. (actually 2...!) But I've never admitted to being anything other than an avid collector, and I've never said such rare plants were ipso facto superior. (OTOH, I am willing to say certain common plants are horticultural POSs and shouldn't be planted!)

It's funny if anything I would have thought I would get in trouble here for implying adelgids aren't a problem anymore! Around here that doesn't seem like the case anymore, but as raymond's trees in SE PA show, it still is a problem in some areas.

Final twist - I'm glad I'm not worried about keeping the big ones I had alive anymore, because 'ever helpful nanny state Maryland' has banned home use of neonics by the non-trained. (well after I carefully treated my trees. I saw no impact on local bee populations) I can actually kind of see the rationale for that, though. I just worry about where it could lead...I'm sure there are people in this state who'd like us to be like NY, where basically any useful herbicide is either banned or illegal for homeowners to use. I needed their shade for a while to get my rhodie beds going, but at the same time realized they were just too big and too old, and had never been pruned correctly over the decades. Also, I thought that there was always the risk the biocontrols would eventually fail and the woolies could come back.

go little beetle!

https://en.wikipedia.org/wiki/Laricobius_nigrinus#/media/File:L_nigrinus_adult_feeding.png

David, you’re not in trouble and we don’t need to add drama where none exists. I was merely curious why you have an unfavorable opinion of T. c. It is completely understandable why a large forest tree might not be suitable in the garden. I do appreciate you explaining your position in more detail. 😊

It's all good with me david. I understand completely.

I like to 'Push the envelope' too. 😎

Here's the post I made on my brother's south-central PA hemlock.

https://www.gardenweb.com/discussions/6477891/young-eastern-hemlock-w-adelgids-doing-ok

There is a picture of Tsuga canadensis and Tsuga canadensis sargentii in Dirr’s Hardy … that caught my eye when I first got interested in gardening – and those photos made me want this plant. That was many many years ago and when I had the opportunity a few years back, and because of its shade tolerance, I put some in as a hedge / screen. Unfortunately, I just couldn’t grow it but wish I could.

Older specimens of Sargent’s Hemlock can be quite spectacular, but they do need some room. This one is at the New York Botanical Garden taken in early May. There’s a more impressive specimen at Berkshire Botanical Garden in western Massachusetts, but I can’t find the picture.

Some say the weeping hemlock is one of the most attractive weepers. I think I remember a very nice one on the Swarthmore College campus (PA).