I have just purchased a dwarf plum tree and a dwarf cherry tree. It says to put them into a 24" minimum pot but all the pots come in litre sizes. I understand that different shapes will hold different amounts but what is 24" approx in litres for a pot. Or I can plant them in the ground but will this encourage them to grow taller? Its a pixy plumb tree. Would a 125lt pot suffice? My plan was to plant them in a large tub, then sink the tub into the ground so it looks like its planted but i dont want it to grow too big