Just to confirm earlier points made on this topic, Clematis are worth growing in mediterranean climates. You might need something to cover the bare patches left in summer, however. My Clematis are springing back to life after summer. Clematis 'Piilu' died back to ground level but within the last 2 weeks new shoots have appeared, about 1.5m in length and it has started flowering. Clematis 'The President' and Clematis 'Mrs Cholmondeley' didn't die back but stopped growing and looked a little tatty. They are starting to show new growth now and should give some autumn flowers.