Old Wool carpet and underlay (Wolverhampton WV3)

We have just had new carpet in our stairs and landing, if anyone can make use of our (7 year old) wool carpet or the underlay.
Carpet is in a decent but used condition it just got baggy on the stairs.
I understand wool carpet can be used as weed control in the garden. It could also suit being used as bits for a garage etc.
You can just have a small section/amount as needed or all of it whatever suits.
Just thought I’d check before taking it to the tip. Thanks