Clematis Elsa Spath massive fail again !

[Billy's lad]

I am trying to create a patio garden on a south west facing terrace and to this end I bought two Clematis Elsa Spath from the garden centre last year which I planted into 50 litre pots of compost and topsoil mix

After some vigorous growth along some sheep hurdles last year one of the plants died off and the stem went black , a bit disheartened I left it in the pot and moved it into the greenhouse in the Autumn

A couple of months ago it was no more than two 2 inch high stalks which as things warmed up started growing like mad up to about 8 foot around the canes so a couple of weeks ago I moved it and sited it against the wall sw facing thinking it was too exposed on the sheep hurdles , I built a wicker cane trellis and it seemed to be going alright until the weekend I noticed one leg was drying up I am watering regularly and my idiot meter tells me it is moist

I thought any idiot could grow these but obviously not this one

Any ideas any one ?The Jasmine next to it is thriving

[nickdub]

I'm not too sure about growing clematis permanently in pots - not something I've tried myself. Hopefully someone who knows more about it will be along soon - in the meantime if you fancy investigating further put a sheet or similar on the ground near one of the pots, knock the root ball compost and all out on to that and have a good look to see if you can find a reason for the problem eg bugs, dryness in one area, damage to the stem at soil level etc.