It is supposed to be native where I live in Sweden but I never saw one so it doesn't behave the same way here. As far as I understand it is found with other shrubs along streams and in woodland edges. Never used as an ornamental around here. Maybe it is different in continental Europe?

A number of different trees and shrubs of Old World origin planted for horticultural purposes in eastern North America have gone bananas there. Invasive plants of alien origin is a worldwide problem costing a lot of money, with which ones being likely to become bad actors in a particular area often not being easily anticipated at the time of introduction. With it likewise not necessarily being immediately identifiable why a particular plant seems to have few barriers to its spread after it has been taking over in a new host territory.

Showing suppliers of Rhamnus cathartica (16 results)

https://www.rhs.org.uk/plants/nurseries-search-result?ID=14452

I was yanking out some buckthorn myself yesterday. Mostly Glossy Buckthorn (Frangula alnus = Rhamnus alnifolia) on and around my property, but European (Rhamnus cathartica) is appearing more and more frequently. At my workplace, European is everywhere.

Interesting factoid: a 2010 study of tree canopy cover in the Chicago region determined that European buckthorn was the single most abundant species.

Interesting that it is so vigorous and overwhelming here compared to its native lands. It does incredibly well in our woodlands, being both drought and shade tolerant. Arbordave, that factoid is deeply concerning, but I can’t say I’m all that shocked based on what I see in my own woods.

Frangula alnus is another story, that one is found everywhere around here

"...so vigorous and overwhelming here compared to its native lands."

This is true of many invasives--kudzu and garlic mustard spring immediately to mind.

I have Frangula alnus, common buckthorn, as my worst pest. My weapon of choice for trees under an inch in diameter is a pair of adjustable tongue and groove pliers. I have relatively loose, sandy loam, so I am usually able to pull trees taller than I am, getting virtually all the roots. I keep track of the ones that are too large to pull and go back later with loppers and brush-level herbicide that I paint on the cambium of the cut stump. This time of year is nice for this job because I don't have to worry about ticks when it's 35 degrees, and many of the buckthorn still have a few leaves clinging. I can ID by the buds alone, but they are easier to spot with leaves. Today I cleaned an area of woods that is perhaps 200 ft by 50 feet, which is a drop in the bucket, but I find that if I continue to work at it, I can reduce the population in at least some areas to levels where they don't get large enough to reseed, so I do find it rewarding. While I was out there I removed a few honeysuckles, which along with bittersweet and barberry are my other 3 nightmares. Since the farm next door went organic and doesn't remove any invasives mechanically as far as I can tell, we are getting a LOT more seedlings of barberry and bittersweet. UGH!

NHB, that is interesting. I’ve got numerous Buckthorns that are pushing 20’, with a thick undergrowth of 1/2” or less diameter trees. It seems every situation is different and requires a modified strategy.

“Today I cleaned an area of woods that is perhaps 200 ft by 50 feet, which is a drop in the bucket, but I find that if I continue to work at it, I can reduce the population in at least some areas to levels where they don't get large enough to reseed, so I do find it rewarding.”

Exactly! :)

I m guessing these Eurasian buckthorns must not like hotter climates, because I never see them down here.

I have been planting R.caroliniana around my place, it's supposed to be native here, but I've never seen one in the wild. I'm hoping they'll reproduce to increase the diversity in the areas I have cleared privet.

I just came across several 10 to 20 footers in my tree line.

one of the worst deciduous invasives n WI. Easy to spot with them clinging onto green leaves when everything else has dropped.