Originally Posted by lannerman

Hi Mike, you dont say where abouts in the UK you are ??? Hydrangea seemanii is a particular favourite form of mine, its bushy, self-clinging and as you say, when it gets going, its quite vigorous. If anything, I'd say that seemanii was quicker to establish the petiolaris ! As for hardiness, I cant comment because, I'm down in the west of Cornwall where its quite mild but even last winter when we had -10 C apart from the very new top growing tips, there was no other damage. One tip that could be useful for you, would be to grow it in a large container in a sunny spot to get it really 'going' before planting it out about early September, that way, you'd give it a really good start !
regards, lannerman.