Dear Camay123:
I keep my trees in a garage from Thanksgiving until late March.
I water the trees well, then I place mulch under, around, and on top of the soil up to the first branch.
You can place the tree in a large box with the top removed. Slit the corner of the box and place a piece of wood at one end (opposite the slit) This is so that when you have to water, the water will run out the slit.
Place a bamboo skewer into the soil and check it weekly to see if it needs water.
I may water the trees two or three times during the Dormancy period.
Here is a picture I took the winter of 2001. All my trees mulched in, they survived a bitter cold winter with weeks in the teens.
