I don't know what others do, but I'm in zone 6 also, and the few times a rose heaved, I just went over and straightened out the bush, applied a slow but even pressure downward as far as it would easily go, and then placed my foot near the base of the rose to apply specific firm but gentle pressure there and kinda walked my way around the bush applying that foot pressure.

I then gave it a good drink, threw some leaves on it, and waited for spring. The rose grew wonderfully that year.

One person's experience. Let's see what others have to say also.

Kate

If it has only heaved a little I think Kate's suggestion is very good. The key is to be gentle because you don't want to compact the soil too much either. For something that's pushed up 6 inches I think you need to re sink it as soon as you can dig the soil. You may not have to dig it out completely but at least enough to get it to settle back down in.

Mulch is probably the best bet to prevent heaving but you can also use soil mounds around the base in the fall. Which is really just a different type of mulch. It will help maintain a more even soil temp. over the winter. Soil mounds are a lot more work but they do have the advantage of replenishing the bed in the spring when you can gently wash the soil off into the bed.

I can't tell yet if I've had any heave or not because there's still at least a foot or two of snow everywhere. I'm hoping that really good snow cover will have prevented a lot of heave.