Don't know for sure, but leaves don't look like prunus.

Not P. serotina (or P. virginiana) which bears fruit on a raceme.

Not P. pensylvanica which has red fruit.

I'm leaning towards Glossy Buckthorn (Frangula alnus)

Rhamnus caroliniana, carolina buckthorn, a native and one of the good guys.

Great pollinator plant for all sorts of winged buggies.

Berries start red, then turn black, birds love them.

Will grow into a small tree in the south.

Berries used in homeopathic medicine, use with caution!

Native on my place, they seed around, I encourage them.

Didn't realize they grew that far north.

Edited to add:

If it is Frangula as smivies suggests, it is non native. The foliage is wider on Frangula than carolina buckthorn, so hard to tell from image.

Edited again:

I just checked the range map, Rhamnus caroliniana is not native to Wisconsin, so smivies may have nailed it.

Glossy buckthorn for sure. Result of use of 'Tallhedge' cultivar. Not your friend.

OK -- thanks for helping with this. I was hoping for the best, but not to be. The list of non-natives growing here just got longer. My will to eliminate them is strong, but my body isn't feeling the same. Must stay positive...must stay positive...must stay positive...

Yeah, it can be frustrating. I rate glossy buckthorn as a distant second from its common buckthorn cousin, in terms of invasiveness. But this thing is showing up more and more too.

At least it won't grow large and they do not cast dense shade so other seedlings should be able to compete with it.

Where I live they are native, and probably the most common shrub. They don't really have any demands, they can handle shade and soil that are low on nitrogen, wet or moderatly dry, acid or alkaline. If you cut it to the ground it will resprout from the stump and birds will disperse the seeds.

You do realize hug, that your description is spot-on for an ecologically-invasive plant species: You've got the bird seed dispersal, the ease of growth in virtually any condition, the shade tolerance......these are the very hallmarks of a troublesome plant species. I said less damaging than common buckthorn, which is just everywhere now, but still a bad actor here in N. America. And 'Tallhedge' is still being promoted as a worthy landscape plant!

here the problem is ligustrum sinese and pyrus calleryana

You do realize hug, that your description is spot-on for an ecologically-invasive plant species

Yes of course. And I can't see how it could be eradicated in a larger area were it is once established. Leave just one or possibly two shrubs and it will come back

I do these things for a living! I am literally one guy you can't tell that these things are impossible. We do it all the time.

Now that said, there are geographic limits to our projects. And what goes on just outside those boundaries can be bad news as far as ecologically invasive plants. But for those areas we control, success is more than just a dream. And I'm at least talking acreage, so that's not nothing.

But Tom, if you stopped maintaining that acreage, the vast pool of stuff on the outside would come right back in.

I'm of the opinion that once a species establishes itself, flora or fauna, it's next to impossible to eradicate it completely, unless the political will is there.

Unless complete eradication of a species puts money in pockets, or exerts power or dominion over someone or something, it won't be done.

Conversely, if the status quo of a species is maintained and it puts money in pockets or exerts power or domination...

if you want to kill a young tree/plant .. of any kind ... cut at ground level .. and apply a stumpkiller or undiluted roundup or generic to the cut.. using the very expensive applicator at the link ...

https://www.google.com/search?q=plochmans+mustard&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a&um=1&ie=UTF-8&hl=en&tbm=isch&source=og&sa=N&tab=wi&ei=XQTcUYCCC_OFyQGCg4DAAg&biw=1154&bih=805&sei=XwTcUbmZHZK4yAHD0oDYDw

this applicator can fall over without significant leakage .. is resealable ... and allows precise minimal usage ... do not store near the hot dogs ...

spraying trees is not really an effective method .. as you have learned .. as they are a vast storage system.. and its hard to overcome that by spraying the leaves ...

same for larger trees .. but you cant snip them etc ... you are aiming for the cambium layer ... so on large trees.. you just need to coat the outer one inch or so .. not the whole cut .... you are not only using the killer.. but removing ALL the canopy.. so you are interrupting the food storage process.. and weakening the tree ...

with clipper and the applicator.. this can become a nice walk in the woods .. rather than a backbreaking chore ...

i dont like to wear gloves... but i sometimes use a chemical rated kitchen glove to carry the applicator around ....

ken

https://www.google.com/search?q=cambium+layer&biw=945&bih=745&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjkuqDh8tfPAhUFOCYKHaHZARoQ_AUIBygC&dpr=0.9

Well Kentrees, maybe we just haven't thrown up the white flag here in Wisconsin yet. There are programs here to deal with this stuff. Wisconsin has always been a leader in conservation technology and I have no doubt we continue to occupy one of the top spots in that arena, even given the takeover here of state government by people with no ethics. I would not be surprised in the least if your Tennessee (right?) state government and perhaps the very mindset of the people in your region are the primary impediments to progress on this front. And to be fair, that happens here too. Lots of people have no idea all that brush growing around their property is a problem. But here in Wisconsin, there is a tradition of caring about such matters, and I think it likely that we have been able to do some things up here that would not have happened elsewhere. It's always been so. Wildlife management, forestry management, stormwater management,...I could go on and on, but these are all areas in which Wisconsin has led the way for other places.......for right around 100 years. It's in the books.

Tom, I'm not singling out Wisconsin, nor your local jurisdiction's efforts at controlling an invasive population of (X). I meant no criticism. All I meant was that unless you eradicate ALL, you run the risk of 'reinfecting' an area you've cleared.

I've just been musing in very general terms.

As far as my state, TN, I really don't know what efforts, if any, are being made on a state level. I know there is an invasive species list, and periodically the news will have a story of volunteers eradicating invasive species at a state or locally owned facility.

I guess the current political situation in our country has me doing more thinking than usual, being the cynic and pessimist that I am.

No, of course we know that. This is the ultimate unending battle. But I don't like people giving up before the battle has even begun. That's all I'm saying.....don't come to a guy like me and say this can't work when we've been making it work for years. In fact, and this is not to say this constitutes victory, but I'm now starting to see some of our "native" plants, quote marks to indicate this was a woods here and these are all grasses and forbs, escape out into the hedgerows and waste places......stands of sawtooth sunflower, or maybe one of the Silphiums....scrambling along a brush line somewhere where I know we didn't plant them. So that's kind of neat to see. Along with all the non-native weeds, some natives can mix in too. So there's that....almost the direct opposite of ecological invasion....the proliferation of "native" species following man's planting of same.

But seriously, Wisconsin really was where almost all of what we now know of as ecology got started; John Muir, Aldo Leopold.....many more.....all did their work here, or at least some of it. I'm more than a little proud of where my state has been, knowing that all over the world, innovations that started here can be found. Lots happened here-for better and for worse.

Now of course, we are being "led" by a pack of tiny-minded fools. Much progress is being scrapped. And for no apparent economic advantage....our state still trails the country in nearly every economic metric.

I keep explaining exactly what kentrees said in the post above. Some people do not realize that. Same thing with burning bush and autumn olive.