Hetty, this is a great tip and one I've used myself from time to time. Even smaller houseplants are usually potted up three to a container and easily divided! You should add your great photo of Cordyline 'Tricolor' to the database: Ti Plant (Cordyline fruticosa 'Tricolor')
~ I'm an old gal who still loves playing in the dirt!
~ Playing in the dirt is my therapy ... and I'm in therapy a lot!