If your bud union is above ground then anything growing from below that point would from the root stock. Yes, that is called a sucker. Do you know what root stock you have. Dr. Huey flower are red. I think multi flora is a single white. It seems to resemble your other cane thou in thickness and thorn placement. Not sure I'm seeing it correctly.

Hope someone else chimes in here. I'm not to familiar with root stock. Dr. Huey is mostly thornless with red bloom. Young multiflora is nearly thorn less and white or pink small single flower. As I mentioned above the thorns on all of your canes appear to be the same. Could this plant be own root?

I would leave it alone and see what happens. It appears to be a nice cane and if it is Iceberg, you don't want to chop it off.

I agree with Rebecca till you see if the rose bloom is something other than a typical Iceberg - as Patty says, Dr. Huey will be a dark red and multiflora is a very small white bloom that looks nothing like Iceberg. Just because a cane is new and healthy doesn't make it an undesirable sucker. I don't see any obvious bud union (graft) above the ground, so you've either buried the bud union if it's grafted (meaning the new cane could be from the "good" rose you want) or it's own root and anything from this rose will be good. Well, the knobby bit on the old cane to the left of the first photo could be a bud union but it's not clearly so, and it might be just some old pruning marks.

The way to tell a sucker is: a) it grows from below a graft, b) it has noticeably different growth structure from the original canes (e.g. thorny and the rose is supposed to be thornless), or c) it blooms a different color from the original rose. If it's an own root rose, none of these apply - everything that grows, even from the bits of root deep in the ground, would be the rose you want. When these are good growth from the roots of the plant, they're considered "basal breaks" and are part of what make a rose bushy rather than one-cane wonders.

Cynthia

Thanks Diane for the great explaination.

Yes, thank you for the great explanation.

When I purchased this rose a couple of years ago, I didn't pay attention to whether it was an own root rose or a grafted rose. It's also entirely possible that I buried the bud union. If this cane is an Iceberg it performed very poorly last year, but I will give it another few seasons to see what comes out of it.

Cynthia, thanks for taking the time to explain that. Yukoyd, I don't own Iceberg, but I have learned the hard way from much experience and shovel pruning roses way too soon, that a rose doesn't perform it's best the first, second, or even third year after planting, especially long caned roses. They need time to develop their roots and get cozy in their space. You maybe know all this already, but it took me a long time to learn, so I thought I'd throw it out there for anyone who might be reading. :)

Yes, leave it alone and see if it blooms this coming Spring. Then you will absolutely be able to tell if it is Iceberg or not.

Jackie

I will be patient then. Thank you again for the advice.

I agree with the decision to wait and see. From the photo, that cane looks to have the exact same "character" as the other canes, only younger,so I think there's a good chance that it isn't understock.

As of today, March 22, the stem I suspected might be a sucker has grown lots of leaves and they look IDENTICAL to the leaves on all of the other stems. I am growing confident that this is, after all, an Iceberg. Now waiting for blooms...

Thank you for all the input :-)

Looks like 'Iceberg'. Enjoy!