Taz, the Euphorbias that I know will work in your area are all herbaceous perennials. What kind is it, Taz, and where do the new spring shoots originate?

I think a photo would be useful - if its a characias type, it should have the flowered stems cut to the ground after they've finished, leaving only the new growth.

The plant is called humpy dumpy' and the shoots are growing from lots of very old woody shoots, that should have been cut out long ago. Can I cut some of the old woody shoots out and will it regrow from the ground

Well you're right, this is one of those varieties that should have all flowered stems removed immediately after they've finished, leaving only the newer growths coming up. Its probably best to sort through what's there, retaining what is obviously new growth from this year (won't be terribly woody), and cutting out at the base all the rest, rather than cutting the whole thing down. Next year, remember to do it once the flowers start fading - by then, you should also be seeing new stems growing.

Thank you to everyone who replied to my question' l will cut back much harder when l next prune.

Wear gloves, Taz - the sap can be highly irritant on some people's skin, and don't get it in your eyes.

A fervent "Oh, Yes!!" to that, Bamboo

Ooh, now that sounds like the voice of nasty experience, Tug!

True! It fortunately didn't leave scars, but I spent a good ten days remembering not to scratch...and burning when I forgot!