What is this please?

And how big does it grow please? Been in the ground for three years and this year has trebled in size... Which is perfect, but if it gets any bigger can I chop it down to size and when is best to do this.. Thanks

 

Hebe sp or named cultivar.

One such as Hebe Purple Pixie.

https://www.google.co.uk/search?q=H...gfrNAhVhLMAKHX-yAT8Q_AUICCgB&biw=1920&bih=971

 

Thank you! Just looking it up and seems it won't get much bigger thank you silver surfer

 

Purple Pixie was just a suggestion. I cannot be sure .
I don't have a great deal of experience with Hebe. We grew a few.
One outgrew the space. It was pruned...and died.
Maybe we did it too hard or at the wrong time.
A hard winter killed the others!