Any starter trees you buy from us have been previously root pruned and put into a plastic pot to recover and start growing new feeder roots. I never recommend putting a tree in a Bonsai pot after its first root prune as it can be very hard on a tree and this is where trees are at the greatest risk of dying. We like to ensure our trees are healthy when they leave us.
Before you start, Potting mix is considered a hazard if inhaled. I recommend only potting outside and the wearing of gloves when potting.
For more information on how to care for your Bonsai go to the Care For Your Bonsai page