Ah, thanks, I'll try this. The drainage *should* be ok as there are two
holes at the bottom of the trough and I filled it with a layer of stones
first.

BUT, it was raining last night, and this morning when I raised the
trough slightly water drained out... I thought the texture of the patio
would be enough to prevent a seal but maybe not.

Thanks a lot,

Tom

Mine has done well this year, for the first time ever, but that was
after I re-dug the whole bed and introduced more compost i.e. just the
conditions it's not supposed to like. It still prefers to go backwards
rather than trail over the wall though