All bar a couple of my acers are in pots ranging from bucket size through to 36” diameter by 30” tall pots. I pot the smaller trees on every year in pots 3inches larger..the large trees that are in huge pots every 3years or so. It’s quite a task having about 65 trees now, and there’s limitations in terms of acquiring larger pots.. my question relates to the larger trees which are about 12-13 feet, last year I removed them from the pots (they’d been in them for 5years) trimmed the root ball at the bottom and a little round the sides, put fresh compost in with perlite and returned them.. They responded to this and were more densely leaved this year. Is this acceptable or should I look at acquiring larger pots? I have a load of floor joists spare so i might make a couple of 4foot cubes. I am moving in the next 18mths so don’t want to plant any.. I will also do some vertical mulching this year..