Question
I have 10 short Emerald Cedar trees now on October, better to planet it now out side or I can keep it in the garage or indoor until next winter?

Answer
In the fall they need at least 6 weeks before the ground freezes. In the spring, Evergreens can be planted up to 4 weeks after deciduous trees have opened their leaves, providing that the newly planted trees receive adequate water. Since you are in Canada I would hold them until the Spring. I would keep them in the garage not inside the house. They will dry out too much in the house. Check the soil every other week and add water if need to keep the soil from drying out but not wet. Next Spring dig the holes twice the size of the root ball and as deep and fill with good top soil or potting soil and mulch around the trees with not more than 3 inches deep of organic mulch not pile up on the trunk.