Just keep cutting the tree off. As with other hand weeding, diligence is the key.

If you are willing to use a herbicide, you can cut off the seedling and dab onto the cut, and on the surrounding bark, straight Roundup (which has glyphosate) or Brush-B-Gon (or any such product that has triclopyr in it). This needs to happen while the tree is actively growing, so wait until it puts out leaves. If you dab it while the cut is fresh, it will pull the herbicide down to the tree roots without affecting the rose (if you avoid getting it on the rose). If the seedling is very well established, you might need to repeat doing this, but you'll weaken and eventually kill the tree.

I use a cheap foam brush to dab the herbicide. We have two pecan trees in our neighborhood, and I get literally hundreds of seedlings thanks to the industry of our squirrels.
Anita

I've had excellent results with just cutting seedling trees to the ground with pruners or loopers and applying a few drops of full strength broad leaf weed killer to the stump to kill the root. I have to do this all the time with hackberry and pecan seedlings that come up under my Mother's roses. These particular trees also develop deep roots early on and have usually become too large to pull out by the time I get over there to take care of them.

Wish I could come there and help you with it. I just pulled up an green ash seedling from Wllm Shakespeare 2K today.

How large is a fully-grown Miss Atwood, by the way? I have a baby, and want to know what to expect in size.

Jerome

>Jerome said: How large is a fully-grown Miss Atwood

I'd love to know the same thing, as well as what you think of this rose in your yard. I haven't ordered it yet, but I'm thinking about it. Any shade tolerance that you've seen?

Best wishes,
Mary

My Miss Atwood is still young so I can't say anything about its eventual size. Mine is in full sun and it's a vigorous, fast-growing rose. The blooms are getting larger as it gets older and surprisingly (at least in the cooler part of the year), when cut in tight bud has made a good cut flower in the house. I'm beginning to like this rose more and more.

Ingrid

Hi everyone, thanks for your ideas.
Miss Atwood is around 6 or 7 years old and I love this rose! No disease, maybe a little powdery mildew in cool rainy weather. The sun doesn't reach MA until 2pm.
Miss Atwood is more broad than tall. She is sort of a neat very bushy plant because I prune her down about 1/3 her size early spring. By August she will reach a size about 4'tall- 5'wide if my memory serves me right.
I am going to try and post a picture on the gallery.

I might try cutting the seedling a few inches and carefully paint roundup on it when the seedling leafs out. But I looked more closely at the base of Miss Atwood and there's also a bunch of nut grass weeds filling in around the base of it! I will try pulling them all out and then do the roundup after the seedling leafs out. If that doesn't work then I will wait till next winter to dig MA up and replant after pulling the seedling out, hopefully no nutgrass will grow back!

Ah, the industrious squirrels! I've had oak seedlings and pecan seedlings -- very tenacious. After trying mechanical means and failing, I resorted to a more devious method that was quite successful.
There is a product called Vinex, which I believe is a brand name for triclopyr. Don't be fooled by the name -- Vinex is a systemic herbicide that kills a lot more than vines. It comes with a little built-in applicator. All you have to do is paint a couple of inches of the stem (or is it already a trunk?), the closer to the ground the better. If you apply as directed, the only thing it kills is the offending seedling. It is a powerful herbicide that should only be used in very small doses.
One giant caveat -- whatever you do, don't get it on anything else in the garden, including the ground itself. It would be the equivalent of giving a sniper a machine gun for a weapon.
My local nursery carries it, but not all do. Good luck -- and wear gloves when you use it.

I had daffodils in a bed before I planted roses. I thought I dug them all up 4 years ago. But suddenly a bunch came up all around my Moondance. They were entwined with the roots. So I dug up Moondance (I didn't like the way he was sitting anyway) and took out the daffy sprouts and replanted them somewhere else. If the other methods don't work, don't be afraid to dig up and replant. I've done it a few times and unless you do it mid summer (yes, I did that!) you should be fine.

"I might try cutting the seedling a few inches and carefully paint roundup on it when the seedling leafs out."

You can apply what ever weed killer you decide to use directly to the stump of the tree seedling. Happily, there's no need to wait until the seedling leafs out so that means you just have to reach under the rose bush once :-)

In my yard nut grass keeps coming in with compost which contains horse manure. Evidently the horses have been eating nut grass with seeds. It's hard to get rid of it by pulling since it always leaves some roots behind so I've used a specific remedy for nut grass called Image. There are other brands available also.

Good luck. BTW, I'm looking forward to seeing photos of your mature MA.

Here is a link that might be useful: About getting rid of nut grass ...

I think buford has a point. I had a Mme. Lombard planted too close to a path (had no idea how huge she'd get) and for 5 years the guys kept cutting it back when it went over the path, but it was getting uglier and more lopsided each year. Finally, I couldn't watch anymore, so I dug her up and moved her 5' deeper into the bed. She made it and is putting out fat new shoots all over the place. If you are going to do this (dig up M.Atwood) you have about 10 more days to do it....

Wow, my thanks to all you gardenwebbers out there! There is a wealth of information here.
I have some roundup so I will try using that.
My thinking is to prune a few deadly canes out so I can carefully paint the seedling and nut grass.It's even warmer today so it might be best to dig up and replant in December next year if the seedling and nut grass come back.

No matter what I do it's going to be risky~I'll do it so very very carefully, Miss Atwood is one of my most cherished roses:>)
After it dries I wonder if laying down cardboard up close to the base of the rose and placing mulch on top will prevent squirrels from planting another walnut.
Sounds like a big project for the whole yard...