gunnera is related to rubarb so yes you can.you have to see how many crowns there are and split them from each other.im not sure of the wording but they get more than one growing tip eventualy and you can split them with a spade.best done in early spring just before they start growing but it is quite a forgiving plant.is your name guest or are you a guest ? if you are you should join up as its a brilliant sight and comunity of all skills and knowledge run bye very nice real people .take care i hope ive been helpfull .

This is absolutely true - I have a large plant, and in the spring 2 years ago, when I was tidying the plant, cutting dead leaves off, etc, a piece came loose. I dropped it onto the bank of our stream - and it grew there. It's now a respectable sized plant!!

So - yes, you can take a piece and it will root easily. Good luck!

Aslong as the bud you remove has atleast some root then it should grow fine. Spring is the best time as Nosey says

Splitting is definitely the best way for a mature plant. i have never tried to propagate one, but i suppose they must start somewhere. When the seed heads are really dry, sow them and put them somewhere warm and damp. They might grow.