Posted: 18/06/2014 at 14:28
If it is clematis wilt there is no need to destroy the whole plant. Just remove the affected stems to the base and then give it a good feed of liquid tomato or rose fertiliser to provide a tonic and encourage new stems to grow. Do this for a few weeks to give it a chance.
New clematis can take a year or two to get established and grow strongly. It helps to pant them at least 4" deeper than they were in their pot and to provide plenty of soil conditioner such as well rotted manure or garden compost when planting and then as a mulch every autumn. In spring, give each one a generous dollop of specialist clematis food which will release nutrients slowly plus a drink of liquid rose food.
Clematis are very hungry, thirsty plants so keep up with the nutrients every year and make sure they don't dry out but don't drown them either. Yours looks as though it is very close to a fence so may be in a bit of a rain shadow. If so, water it thoroughly and then mulch it to help retain moisture.