West Sussex,
United Kingdom 
I want to buy a 2 year old potted clematis "Wesselton" but will not have a site for it until next spring. Would it be ok to buy it now and keep it in the pot over the winter or would I do better to wait until next year to buy it? I'm just slightly worried that I might not be able to source one if I wait.
I used to have a magnificent one of these but lost it when I hired a man to clear an area of garden and although I marked the plant and showed it to him he somehow managed to raze it to the ground and it didn't recover!
14 Jul, 2019
Answers
Yes I'd buy it now but repot into a bigger pot and don't forget to keep it well watered and the pot out of direct sunshine. protect it if the forecast is for severe weather.
it is a group 1 so it is an early flowerer so don't cut the stems back this year as you will lose the flowers in the spring.
14 Jul, 2019
Buying now & putting it in a big pot might have upsides in that you could give it out of season snips & feeds to maximise the number of stems?
14 Jul, 2019
But if you waited Darren, somebody else would have done all that for you - - the babysitting. Just saying.
14 Jul, 2019
I would wait until next Spring. It's widely available now so you shouldn't have any problem sourcing it next year. Someone like Thorncroft Clematis will have it. RHS site also says the 17 nurseries have it.
14 Jul, 2019
I would contact Taylor's Clematis and ask their advice. They are a very reputable firm - I've bought several clematis from them
14 Jul, 2019
Thank you all. Thanks Jimmy and Andrew too for recommendations of stockists. I'm weighing things up!!
15 Jul, 2019
For your sake, I would wait until next spring. Otherwise you'll feel like you've adopted a child. I'm sure you'll find one next spring. Half my plants I get through mail order. Somewhere, someplace, you'll be able to source one next year or you may find another you prefer. That happened to me with my Coral Honeysuckle. He's now my x-gardener.
14 Jul, 2019