Hardy Tropicals UK

Ive had this astelia planted for several years but it has grown too big. Can these be divided or pruned in anyway?

That's a nice plant Lizzie.
I've divided them just like any normal perennial, but having said that, I'm sure I read somewhere that they dislike root disturbance! The worst that will happen is you kill the plant....or fall off the wall

Thanks flounder.
Falling off the wall cannot be discounted.
Yeah it is a great plant. I had this year decided to finally do an arid bed. Dig out all of the gritty soil and replace it with 100% grit and get some agave's in, my aloe polyphylla and a yucca rostrata etc and the astelia is slap bang in the middle of the bed.