Hello and welcome to GOY James.

Wow thats huge sorry dont know what it could be.

Looks like Phormium, not sure which variety.

I would say Phormium tenax, or as my son calls it,
TRIFFID, lol

I think it is a yucca - we had one like this when I was a child.

It's amazing according to my bit of research it's probably a narrow leafed Yucca here's the link http://www.texasbeyondhistory.net/plateaus/nature/images/yucca.html

I cant decide on yucca or phormium. I'm more inclined to Phormium as mine have flowered and I seem to rememeber the flowering spike like this. when they open post another photo and we will be better able to help.

welcome to GoY too.

I'm sticking with Phormium - I can't see any short trunk at the base of those plants, and the leaves look too lax for Yucca. I wonder if they have a sharp thorn on the end - if they do, then its Yucca.

True, Bamboo - they do look a bit bendy!

Phormium, not yucca .

I think it is a form of Phormium, tenax being the more common to flower. If you are lucky you may get some lovely red flowers. if not quite so lucky they will be a dirty mustard colour.
I love these plants, the leaves are excellent to use as plant ties if you split them down.

Phormium tenax. They have orangey-red flowers that are filled with shiny black seeds afterwards, which germinate quite easily. They take 10-15 years to reach the size in the photos.

Phorium tenax is quite often used by landscapers as they are large and take little care (severe winters can kill them though).

That's a good idea, 2ndhand!

Thanks to all that answered
It seems , by consensus , to be a Phorium however, it did not have a coloured last year. It did have lots of black seeds

I 'm almost sure its a New Zealand flax. We were given ours years ago and it actually came as a young plant from New Zealand. It also took about 10 years to flower and it was huge and at least 10 foot high.

Thanks Rose1949 for your answer .On reading up on New Zealand Flax I see it is a Phormium