Concolor fir tree: Repot now or wait?
Hi all. I just picked up a small concolor fir (Abies concolor) seedling from a local store on clearance for less than $5.00. The tree is about 18" tall and looks to be in decent condition, at least he part I can see. It's growing in a 1 gallon plastic container. I have no idea what the roots are like but I'm guessing they may not be in great condition. Currently it's growing in what looks like a combination of fine peat and sand, no pine bark or perlite for sure.
Since the trunk and branches look to be in decent shape my goal is to move this tree to a container with better soil mix, like a 5-1-1 or possibly a gritty mix.
Question: I'm not sure if I should try and bare root the tree and move it to the new soil now (late August), or wait until September/October when it's cooler. I'd like to get this peat/sand soil mix off of the roots and get the tree established into a much better soil before winter begins. Even if I do bare root the tree this year I don't plan to do any root pruning, hopefully, until early spring next year. If the roots are in really bad shape I might have to do some minor root work. Hopefully that can wait until spring.
If I do move the tree to a new soil mix, what about adding fertilizer this late in the season? Normally I mix in Osmocote Plus CRF into my soil mixes but not sure if that is a good move this late in the season.
Any advice? I can post a photo if it would help.