Thank you all for your responses.
Gosh,Seil, I find it hard to answer your question; I actually don't even remember from whom I bought this plant! Let me tell you the history,if you have the patience. I'm pretty sure I got it bare-root,years ago-how many I can't say. I had a very challenging health situation with which to cope that peaked around 2018,so the trauma of this "interruption" makes my memory of the year or so before that rather blurry. A lot of other stuff was going on as well; we moved into this new house in November of 2015. So let's say I got it bare-root around year 2015/16. I think I started it out in a pot,since it wasn't a very large plant,grew it on for a year or so, and then planted it out in my garden. However I did not do a good job of planting it; it was in this area that flanks the road, from which the land slopes sharply down. There is very little soil up in this area. When I hired a man to come out and sort of fix the road, he did some clearing with his -what do you call those big shoveling -type machines; not tractors.... He dumped the soil he dug out over the fence on my request,to plump up the area,but it wasn't enough, so I brought in soil I'd bagged up from other places and sort of squeezed GdD in anyway. I seem to remember that it had not had time to develop a great root ball ,either, but I figured that since it was supposedly vigorous that it might be able to cope. It did cope, but was not flourishing ,so I dug it up and potted it again. Last spring, I moved it into a larger pot,thinking this might give it a boost, but this didn't work, so recently I moved it back to a smaller pot -18 cm diameter by 21 cm deep.The plant itself looks good and healthy,and the fact that it survived all this speaks well for it,but I don't think that this variety is what I would describe as particularly vigorous.