Since your Zone 3, you may be interested in learning about Alpine Gardening.  This group of gardeners are unique breed within the gardening world.  Some learn Alpine gardening due to there Zone and others mature to Alpine gardening like a fine wine.  

This is a very difficult type of gardening, but one you need to learn due to your Zone. 

If your considering plants for a pot, and you want them to be around for next year, I would recommend reading about Tufa gardening.

Hmm... lets see if I have any links...

http://www.backyardgardener.com/index2.html

http://www.backyardgardener.com/tufa.html

http://www.backyardgardener.com/shade/zone3.html

http://garden.lovetoknow.com/wiki/Gardening_Zone_3

Nursery http://backyardgardener.com/mttahoma

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