I think cutting back to ground level would be too severe and will kill it. see what everyone else thinks.

Hi Choysia are pruning group 8, which means a light trim after flowering, to keep the required shape, but as you've already cut it back, you will have to wait and see what it does, it may grow back for you, but as Sbg says, I wouldn't cut it back any further than you already have, Derek.

Sorry to disagree but I have a mature and large Choisya which is about 18 years old. I have cut it back to the ground 4 times and it always grows back. I have been on holiday and have only just see this post.

that's good then. as I said I wasn't sure but the rHS pruning gp 8 suggests that it wont regenerate.