What size planter for 30cm buxus ball?

[Potentialpoochowner]

Sport for my ignorance! If I have a bucks ball which is 30cm in diameter at its widest part, could you recommend what eize planter to get for a square shaped planter, and a tapered one?

Depending on how fast they grow I think I'd look tobgrieingbtge Bucks ball to about 40cm

Tua

Oh god, iPhone autocorrect awfulness!

1 buxus ball
2 I'd look to growing it to 40cm if they grow fast
3 TIA

Thanks!

As far as I know, it's the same for box as for anything else. Have a look at the diameter of the top of the pot it's currently in, and go for one a couple of sizes bigger!

The question is really the size of the roots, not so much the size of the ball (though a certain size of ball kind of implies a certain size of root IYSWIM). Have a look underneath the pot to see if any roots are poking through (sign of being potbound), and at the edges to see whether it's just loose soil there or whether it's quite tightly packed in. If it's very potbound, perhaps go for a slightly larger replacement pot.