Hi Rene
I think you have a really nice group of boxwood there and if they are anything like they are here in australia they grow slow and very compact..nice for groups.
I think the number 1 tree being bigger is great, but im not sure about the twin trunks. I see the group as a more rounded or a group of broom stlye trees rather than tall and thin. Mind you it has lots of options for the future.
If there is a trunk behind the number 1 tree...lets see him

Id bring him out towards the left with the rest of the pack of trees. Also maybe the trees need to be straightened up a bit if you go with the broom-ish style forrest but the spacing is great, very natural.
I just love the pot, but i have a thing for blue pots and the moss..wow. I think the pot is the perfect size for the group but the trees are a little too high in the pot. you can make the muck wall thinner and lower and it will still all hold together.
Id love to be looking after this group in the future...so much so that i made a quick little virtual...
cheers
Juliet
