Likely depends on which globe thistle. The one we have, which I've taken as the species, Echinops ritro, at least in my experience, is a much larger and more robust plant than the several named cultivars we have/have had. Just had to cut some of the species back yesterday.

The one which I have in the front has grown mammoth this year, even after dividing it way back in early spring. It's over 5 feet! Last year worked really well beside asclepias incarnata (swamp milkweed) which was about the same height and both drove the pollinators crazy. Oddly, this year the milkweed seems to have disappeared, or may have become engulfed with the other things I have vying for attention in that space. Anyway, this year I added a trumpet lily beside it and that seems to be a good fit so far. Next year that thing is going to be cut way, way back. I'm tempted to do it now like sunnyborders, but it's just getting ready to flower, and there seem to be even more blooms than normal, running down the stem and not just at the end.

Mine are in a patch of about six plants planted against a fence (then there is a smaller patch of four in a different location). The six-plant patch is older and is huge, and there are Gaura and burgundy Gaillardia planted in front in patches. The burgundy Gaillardia is iffy, since it doesn't reseed true, so I'm going to replace it with Centranthus. The Echinops came from seed from a friend, so I don't really know what kind it is, but I love it.

Interesting comments on globe thistle above. I'm currently quite confused on the subject. Our No Name Echinops is as tall as LaLennoxa's. I'm beginning to think that this Echinops is an (old) garden hybrid, perhaps of Echinops sphaerocephalus great/white globe thistle ('Arctic Glow' has apparently been around here for some time) and one or more E. ritro (globe thistle). Things like the mature globe colour and stem colour may not fit, but the size (and perhaps the overall triangular shape of the leaves) may do so. Dwiggins mentions seeding. I always deadhead ours.

Still have to say that the apparent garden hybrid is a much more impressive plant than an E. ritro like 'Vietch's Blue'. Think lots of summer perennials will look good with (e.g. garden phlox), but whatever is used, it should go in front!

There's an old globe thistle at the historic site that's been in place for at least a decade. In the past couple of years, it has begun spreading from the roots. It wants to be a massive plant and I've been imposing firm discipline upon it. I have no idea which cultivar it is. I don't deadhead because birds like the seed, but it doesn't pop up in other garden beds. I guess it's four feet tall and the patch is 3x6 now.

It's been at least 15 years since I threw down seed, and it's taken that long for my plants to reach almost 6 feet in my 6-plant patch. The 4-plant patch is younger and not as tall, but shows the same type of height growth (app. 1 inch/year after the first 3 feet). My friend's plants don't exceed 3 feet, but are growing at 7,000 ft. altitude with minimal supplemental irrigation. My plants get regular drip irrigation, but at low levels, and are only at 3,000 feet.

Even at 3,000 feet, sunlight is intense and summers here are hot (over 100 for the next two weeks). The thistles get at least 10 hours of sun, and take it very well. Really tough plants.

I'm envious of the growth rate of LaLennoxa's plant. Also, I deadhead the plants. I know there's no such thing as a 500 per cent germination rate, but that's what it seems like if even one flower is left to go to seed.

And I hope my plants don't start spreading from the roots. How would I know? What does it look like?

my very limited experience with thistle.. would indicate that you would put nothing near it. that required you to go near the T ... for fear of losing blood .. lol ...

ken

Thought I would include pictures if the monster I have growing in the front. I think it's the third year in the ground, and honestly, it is doing the "leap".

LaLennoxa, your plants look to be the result of moderate warmth, good precipitation, and a loving hand.

Dwiggins, I think that's the sweetest thing anyone has said to me all week! I'm touched :)

I'm actually contemplating moving it to the back of the bed, right against the wall. It's difficult to see from the picture, but it's towards the middle of the bed - there's a space in front the downspout where Echinops could live happily, methinks! Plans for 2018...

Going to move one against a wall as well. It's so big and occupying space in full sun that I want to use for something else. Will deadhead & prune to keep it under control.

When you all talk about cuttibg it back do you nean a chelsea chop? Becsuse they die back to the ground every year in my xone 7.