Yucca- pot or ground?

My father in law has given us a yucca today. He grew it on from a sprout of his plant, which is 3ft tall and described by him as a triffid. It's about 30cm tall at the moment.

Do I put it in the ground or play it safe in a container? I'm worried it might turn into our 10ft pampas grass (which I'm already dreading dealing with when the time comes!). I don't know how big yuccas grow, any hints/tips welcome. Not sure what to plant it with either as it doesn't fit my current garden style...though I do have some acers on the way which is a new thing for me.
I could redo my back flower bed next year with the yucca central and a little lavender hedge/lady's mantle or some annuals around it? The soil is free draining and the aspect east and sunny all afternoon/evening.

 

Charlie, They grow big, I had a little one given to me years ago I put it in the ground and after a couple of years it was like a small tree, The flower is a spectacle to behold altho short lived. Funny thing tho its spikes are wicked A robin built its nest right in the centre , No predator problems there, smart little birds Robins.