i'm too tired to google these myself to see if they're the ones you've got, but note that Euphorbia myrsinites, E x martinii, E. nicaeensis, E. Rigida and E. characias and all their sub species and varieties have bienniel stems; 2 types of stem present at once, the previous season's stem which will produce flowers, and the current season's growth. The flowered stems should be cut down to the ground during late summer and autumn. Hope that helps a bit

I think I have already answered this one ages ago?!? They probably won't respond to this answer and will probably ask it again later.....

I do beg your pardon Guest. I have looked back and find that you are a different person to the one I was referring to (blush...)