Seems to me that it is trial and error. I've seen vague, non-specific references to roses that don't thrive on their own roots, so I'm assuming that there must be some.

I read something recently (probably on one of these forums) that the HT Henry Fonda did not perform well when J&P attempted to market it as one of their New Generation roses. Other than that, I've yet to find anything regarding roses that always do better as grafted plants.

It is all trial & error, as each rose has different roots. For the slightly tender roses I for one feel safer with grafted (Dr. Huey or multiflora, they both do fine for me).

I got two G. Jeckyls last year, one own root and one grafted on multiflora. They both came through the winter equally, and are both blooming the same so far. I see no difference whatsoever.

I have heard the opinion that multiflora does better in low PH soil. That seems to be my experience here. Own root and Dr Huey do better than multiflora in my high PH area. That's a guess at best with no scientific data to back it up. Good luck.

Multiflora does so well in heavy clay soil that it is banned as an invasive weed in Connecticut.

Here is a link that might be useful: Status of Multifora in your state?

With some roses, one does not have any choice if you want a certain variety. If you plant grafted roses deep they go own root anyways. If you plant high they are easier to tip if you engage in that madness. Most of us know when a rose has died back to the rootstock and with RRD we know to be careful in rooting out such beasties promptly.

That said MFL rootstocks love our potters clay.

One book I read from the library, can't remember the title, advised if that certain variety was vigorious enough to be grown own root. If J&P selection is OK for you they only offer some roses on their own rootstock.

If your growing season is one month long grafted is preferable. The first rose I bought, Tamora, is sad and wishes it had been grown own root. I am going to place the shovel by it and see if it improves.

Sorry to ramble.

Foghorn

Wow, thanks for all the help here. No, I don't tip any roses...and I do plant deep. We have very clay soil (we have to amend alot-believe it or not, "Clay, NY" is the name of our town), don't know the pH exactly, except to say that when I tested it a few years ago, it was in the right range of "slightly acidic"....
I just wondered if there were any hard and fast rules about choosing.....
I guess I'll continue doing what I'm doing...
Thanks again everyone, for your input! I'll put it in my "notes" section here on gardenweb.
:0) Phyl