How do I take care of my tree roses? Is there special winter care?

Tree roses are not hardy enough to stay outside in the winter. So ideally you have hopefully left them in some sort of pot. Continue to leave them outdoors, keep them well watered through the autumn. Come about Thanksgiving, they should be dormant- all the leaves should have fallen off of the rose. At that point, you want to give the pot a final deep watering. (I like to leave a tray under pot, let it absorb as much water as the soil can take) Mulch the pot with 2-3" of wood mulch. Then bring the pot into the garage. Each month either water if it is above 32 F, or put snow on the pot, to keep the rose's root hydrated through the winter. Snow is ideal, because it will melt slowly, without making an ice slick in the garage! Keep up with slow hydration until nights begin to climb into the high 30s, low 40s. Then it is time to bring the tree rose back outside! If it begins to bud out new leaves and there is a chance of snow or hard frost, bring it back into the garage to protect the new leaves. Prune any dead cane and fertilize with about 1/2-1 cup (depends on how big the pot is) of Espoma Rosetone as the rose tree breaks dormancy in the spring.