Unless they are very small I think I'd plant them outside now. Japanese anenome ,are ,from my experience ,tough as old boots.

I would get them planted now so they can get established and give you the pleasure in May.

I have been looking for this one myself.

Its a beauty.

umm! they have some tips on the crocus web site where its on sale personally if these have been sent to you by someone like t&m they will be very small its spent its life up to now in a pot from a cutting so imo i would just put it in a bigger pot as its easier to check on than trying to find it time and time again in the garden winters can be dry! i would worry about drying out ? then plant it out in spring ive lost so many things bought at plant fairs in sept and planted out they just disappear !

I tend to agree with Youngalistai if they are very small, I think I would start off in pots.

Agree with Anchorman. Tough as they come. Persistent too if you decide to remove them....unless you clear every last tiny bit they will eventually regenerate. I think all plants should be numbered with a 'thug warning' 1-10. That said it's a lovely plant....so long as you know before you plant.

Thanks to all who have given advice. There appears to be two conflicting ideas SO, I think I will follow both. I will keep one in a pot and plant the other. Will let you know next year which fares best. Thanks once again everyone.