Colorado Blue Spruce

Question

I have planted (from seeds) Colorado blue spruce trees. They are still in pots and are 18 to 24 in. high. Do I now plant them in the garden or leave them in pots to put in the shed in case the weather gets too cold?

Answer 1

Yes, since they are still quite young and tender, I would allow them to overwinter in the pots until spring. These trees are typically hardy to zones 2-8, so the cold itself should not be an issue. In a container, however, plants experience weather more like zones one lower because they do not have as much protection from the cold for the roots as plants in the ground.

To be on the safe side, the roots may still require some protection during the most extreme temps in winter by wrapping the container in blankets, bubble wrap, or quilt batting. Alternatively, you could simply move them to an unheated garage if it gets too bad outside, or if the container they are in is not really cold hardy (such as with clay or terra cotta). As long as the roots are protected though, they should live through the winter just fine as is.