If she's in southern Ontario (zone 5) she can just put the pot in an unheated garage and water it every 6 weeks or so. I usually overwinter about a dozen potted roses that way each year. Own root roses do great in Ontario. Depending on the type (hybrid tea, shrub, etc.) some will need more protection than others. My northern Michigan climate is similar to much of Ontario's climate and I grow a wide range of ownroots. The hardy Canadian ownroots do not take any winterizing - ownroot hybrid teas, floribundas and more tender shrubs take a little to a lot of winter cover.

If she decides she does want to try burying it, then wait until after a hard frost to add the mulch. Put a cage around the rose of chicken wire or hardwire cloth then fill it with the mulch. Hopefully most of the mice will have found homes by that time, and the cage should discourage moving in.

Two years ago I decided to experiment and see which potted roses did better - those I buried or those I stuck in the garage. It was a real chore to dig the deep trenches and bury the roses, but I would be willing to do it if it was best. In the spring, I dug up the buried roses and brought out the garage guys. Those that wintered in the garage looked much better right off the bat, budded out quiicker, were much more free of canker and other disease, and performed twice as well that summer. Needless to say, all my potted roses go in the garage now. The only thing I have to be sure to remember is to water them every 6 weeks or so, because although they can take the cold of our unheated garage, dehydration will kill them.

Thank you.

I wondered about the own root roses cause sent one of mine to friend in MI and it returned& did well for spring blooms for her.It was Aloha.
she can proably d the garage.Thanks.

...Exactly what Karenforroses says, except it also helps to ensure that the pots are not placed right up against the wall of an unheated garage, or directly on the floor. If you have a shelf to place them on this would be ideal and even better would be to place them in an enclosed storage shed if you have one in your garage.

Good luck.

Right, Morden Man. I should have added that we keep the pots on wooden slats so they're not sitting right on the floor. We also put a large sheet of styrofoam against the back wall behind the roses. I've never lost a 'garage rose' yet, but I am careful to keep them hydrated (l/2 cup water every 6 weeks or so).