When buying a potted Christmas tree, what you don't want is a 'normal' tree that's been dug up and shoved in a pot. Let loose in the ground, the trees will tend to spread their roots much more widely, and when trees are dug up many of these tend to be cut off or damaged to squish it into the pot. That pretty much inevitably means the tree is going to struggle to survive. Our trees are grown using 'Easiroot' pots, sunk into the ground. These pots have teeny little holes to allow micro-roots to poke through and benefit from being in the ground, but with the major root system contained to the pot. When we're ready to harvest, the whole thing - along with the pot - just gets pulled up out of the ground and hey presto, you have yourself a living Christmas tree that's got a much better chance of ... well ... living.
The tree will arrive in this agricultural "growing" pot, which (because it's been buried for several years!) will be muddy and in some cases bursting at the seams from all those healthy roots! The pot is designed for growing and transport (in a bag to contain any mud!), but you will probably want to use a decorative pot around it for Christmas, and replace the plastic pot when the tree is ready to go back outside.
