Q.Fertilizing colorado spruce first spring after fall planting
They are approx. 12 ft tall. Would like to know amount of fertilizer as well. I am outside Calgary and do notice a fair bit of winter burn, more severe southwest side of tree.

Certified GKH Gardening Expert
The amount of fertilizer depends on the kind you buy, so it is always best to follow the manufacturer's directions on the package.
A balanced fertilizer or one that is slightly higher in nitrogen would be your best bet.
This article may help you with the winter burn:
https://www.gardeningknowhow.com/plant-problems/environmental/winter-burn-in-evergreens.htm