Euphorbia polychroma - 2011

Can I ask you, Andrew, if you could tell me the age of this plant, and does it stay as a neat clump, or is it invasive? Thank you!

Libet - it's three years old. This is one euphorbia that stays put and makes a nice clump. All I do is cut it down in early spring and give it some discrete support just before flowering to stop it splaying (if you look to the left of the viola flowers, you can just make out a link stake)

Oh gosh! yes Andrew! It took a minute but I see it now, very discrete! It's a cracking plant, I think I'll give it a go now you've given it such a glowing report! Thank you very much for taking the time to give me your advice!