It's best planted in the fall when it's dormant.

Thank you very much, NoBreyner. I SHALL take your advice and plant my next maple in a pot in the Fall. I planted my first red split leaf maple in a huge pot last spring. It seems to be shrinking a bit; and the leaves that were exposed to the most sun are sun-burned. It was planted by a nursery with sticks of fertilizer in the soil at the time of planting. I have not fertilized since, but have watered -- at first daily, and then later approx. every other or every third day. I am keeping my fingers crossed regarding it's survival through the winter. Any suggestions will be most welcome. It has been situated in an outer corner of my 3rd floor balcony. I plan to move it closer to the building to protect it from winter. In your experience are the other ("Blood-something") maples hardier than the fragile-looking split leaf ones? I am seriously considering planting one of the latter in the opposite corner of my balcony. That end of the balcony gets less sun. Or would you move the more delicate one to the shadier side of the balcony and place the hardier one in it's place?

Marion