I would like to know if I brought my basket of mum's inside when we have the first frost and winter them over if they will return again next year or if the chance of them returning still remains 1 out 10 that come back.
My sister up in Maine cut hers back and brought them in. They did survive in a sunny window and were cut back again this spring and planted out. Whether it's worth doing is another question.
If you plant in the spring, the rate of return is greatly improved. Good drainage is required and do not cut back in the fall. Bluestone has a nice selection for spring shipping.
Put them in the garage and don't cut them back. Water once a month sparingly - don't soak them. In the spring you can begin watering again when they start to green up, but take care not to leave them outside during a frost or they will be killed. Have kept a pot mum - Sarah in a cement basket for 3 years this way. Honestly, if you can find a grower that will sell small mums in the spring, you are just as well off.
I planted a bunch of pot mums last fall in a raised bed beside the driveway with excellent drainage - which is the critical issue for overwintering mums. To my surprise 4 of them returned. I attribute it to 1) not cutting back in the fall 2) mounding leaves on the mums over the winter, and 3) not pulling the leaves back till truly all danger of frost was past.
I've lost mums spring after spring by uncovering them too early - the tender shoots can't take cold weather.
I put my mums in a unheated room, it does not get any heat but it will get some sun from the window. I did not cut them back, but I did cut the dead blooms off of it. It is in a place that I can get to fairly easily and water it once a month. That is what I did wrong with the first ones but they were not hardy mums they were florist mums. So we will see how these turn out.
Cut the dead flowers off but don't cut the foliage. I do this and they all come back. In the spring I cut the foliage back.
This won't help for this year's mums, but there are fully hardy mums that don't need fussing over to overwinter. The two types in my garden have survived here on the edge of zone 4 for more than 10 years. Because of their location next to the front walk, they get cut back for appearance and ease of snow removal. The drainage is good and usually they are buried in snow, but we also have had virtually snow-free winters that they have survived well. I think I planted them in August. One is a short groundcover mum, C. Weyrichii, which blooms in September with simple white daisies. The other I don't know the name of by now if it even had a label when I bought it from a local fruit farm.
Fading after several nights in the low 20's. (I don't seem to have a photo of them in October when they are in full bloom.)
From November 14, 2012