the leaf doesnt look right for loosestrife. it seems to smooth/shiny.

do the leaves have any smell when crushed? its not a typical water mint leaf shape though the growth is reminescent of it.

Habit also reminds me of greater willow herb but again leaf isnt right.

Not sure about the smell as currently getting over manflu and still have no taste or smell!! Been a brave soldier though!!

I take it it's okay to be growing in there though SBG?

I think that it is too 'solid' for a willowherb, Sbg, and that it will bear small, blue flowers in summer. It seems to have a square stem. Is this loosestrife?

I agree about the willow herb BA, they were more 'musings'. Its easy to say what things are not isnt it.
i have just looked up purple loosestrife in my wild flower guide and it looks like it is as you hoped oddbillie.
glad you have been a brave soldier and hope you are back to full duties pdq.

Thanks both and yes, I'm getting there slowly SBG although Ali now has it!!

That's cool if it's loosestrife as I had hoped!