I planted my acer palmatum In november (in a pot) and was worried it would die.
It's tough as anything though!
Kept it protected from winds, in a pot, against west-facing wall of house.
It's a dwarf variety (ma 1.5m tall) and it seems very happy there.
I only water it with rainwater and it has no tray under so the drainage is good.
Pot is about 40cm across and I used ericaceous compost though apparently it can also manage in neutral soil, just not lime soil.
Other than that, it just does it's own thing 