Nottinghamshire, United Kingdom

I've read up and looked at images on the net and mine doesn't look at all healthy in comparison. It's much greener this year but I would like it to bush out or spread a little more. I gave it a mulch and some fertiliser pellets were sprinkled around it too but I see no shoots from the base. Should I prune it after flowering? Is it safe to even cut it right back to encourage side growth, or would that kill it/ stunt it?
I'd be grateful for any advice. It's a 3 year old plant and hasn't changed much since I planted it.
Thanks

• 21 Mar, 2009