Another plant id query!

[Decorhate]

Well a tree really.

This self seeded in a pot & I transplanted it into the ground. I initially assumed it might be an apple tree as there was one just over the fence in the neighbouring garden. But the leaves look different now (smooth not serrated).

This year when the leaves started to emerge they looked almost like catkins

Is it a form of hebe?

It's a type of willow.
We have one, it's gone from nothing to this in 12 years.

Here

If it's a willow you would be best digging it up and putting it back in a pot again. They grow at a fantastic rate and if you leave it in the ground, you'll have the devil's own job to keep it in check.

Bother! I would never have planted it out if I'd known.