Once they have entered dormancy, they do not need any sun -this is true of the evergreen azaleas and the large leaf rhododendrons as well as the deciduous types. What you do have to be careful of is the pots themselves going too far below freezing. The small volume of planting medium in a pot can become cold enough to damage or even kill the roots where they would have been perfectly hardy if planted in the ground.

The garage will work, especially if you put a large carton over them to trap ground heat, so will packing insulating material like oak leaves around the pots in the nursery area if you're not visited by mice or voles. All in all, the easiest thing to do is put them in the coolest part of the cellar where you know temperatures will stay above freezing but keep the plants dormant.

I have used a number of methods of protecting such rhododendrons and azaleas here in SE PA. You do want them to get cold and stay cold. Hence a garage attached to a heated home is probably not the best place. We have an unheated garage far from our house, so it is great to store such plants as it tempers the extremes in temperature and gives a good average temperature.

I have shelves in the north windows and set the plants on these shelves. That way they get light as they come out of dormancy in the spring. I just check every few weeks to make sure they don't need watering. They seldom need any watering. I moved all of them into larger pots before storing since some were in very small pots.

I have used a cold frame set up like a Nearing frame facing north and shielded from direct sun. That worked well. I have set them in a north facing area and buried the pots with leaves leaving the tops exposed to light. A friend puts his in his north facing window wells which naturally get some leaves in them and has excellent luck. Another friend puts his second year seedlings in hoop houses located in an area with high shade. He leaves the ends open. That works well for him.

Actually the deciduous azaleas are probably the most hardy and the easiest to care for. My concern is making sure that even the deciduous azaleas are exposed to light so they know when to break dormancy. That way I don't have to worry about when to move them or uncover them. I just watch what they do naturally.

Great info as usual.

I think most of them will have to go into the unheated attached garage - we don't have anything that is not attached. I hoping the area farthest from the house will work. It gets pretty cold but rarely goes below freezing.

Not much light though. Sounds like light is important in the spring.

North facing window wells - great idea. We have 2 or 3 that I could use. Our "nursery" is on the north side of the house. I have oak leaves in there now, and also have lot of evergreen boughs that I can put over. I guess I could put them over in winter and take them off in the spring.

Last year I had some newly rooted hydrangea cutting in the garage on the side near the house. They had a really hard time last spring with the weather ups and downs, and most did not make it.

Rhodyman - I'm surprised that you said the deciduous azaleas are the easiest - I would think they would be the most difficult because their new spring leaves would be most vulnerable to cold snaps.

Light, but not bright, direct sun, is important, but it is just one factor. Temperature is the other one. What I have always done is move rhododendrons outside to a suitable area once the danger of really cold temperatures has passed - usually March. If you can protect them from driving rain, such as under the house eaves, so much the better. Treated this way,they will emerge slowly from dormancy in synch with everything else so you do not have to worry about premature growth being frosted.

Some deciduous azaleas are difficult. Not because of early growth, but because they are reluctant to break dormancy. If there's no sign of new growth by April/May gentle bottom heat combined with increased humidity - regular misting or placing them under loose plastic - can help.

That is a good point about deciduous azaleas. When I keep them exposed to light, I have never had a problem with a deciduous azalea not breaking dormancy the second winter or subsequent winters, but the first winter is critical. For that reason, I always get deciduous azaleas that are at least one year old and are actively growing. But I also overwinter them where it is cold but has only north exposure to light.

I also have never had a problem with the foliage coming out and getting frosted. But that is another reason to keep them cold and away from heat. Or if they do leaf out early, protect them until the danger of a killing frost is past.

The protection these plants need in winter is from direct sun, cold-dry winds, and sudden extreme cold snaps. In warm-dry winters always check to make sure the plants have enough water, but not too much.