Is it ok to plant a bare root sorbus tree at this time of year ? or should i wait until spring ?
yes. now is fine... go ahead and plant..weather permitting...
Now as they still need some water over winter and if planted now will put out roots.
Are places selling bare roots now? They normally wait till the first frosts force the trees into dormancy, which is late November. I would use your nail to take a bit of bark off the trunk to check the tree is green and healthy.
Thank you both for the helpful information