Can be planted out now. I prefer to plant small plugs into larger pots first then out in the borders after a few weeks. It helps eliminate losing plants due to slugs etc and you can water more/less with ease.

Remember this is a pretty rampant grower, so be careful where you plant it.

Would reiterate what Vincent has said, I used to have this in my old garden and it spread everywhere, a pretty thug.

I'm still trying to get rid of it!