Raised Bed Around A Tree.
Making a raised bed on your fir tree it should be fine provided that the soil does not go directly up to the trunk of the Fir tree as this might kill it. This is the same with all trees you often see developers back fill against trees and cover the first 2 to 3 feet of a tree, in most cases these trees will die after a few years.October is fine to plant any containerised plant so you can go ahead with your project now.