Clematis gone funny
Both my cheapo clematis I bought from Morrisons a couple of years ago have got powdery stuff all over them and they are not really thriving, they made an effort a couple of months ago but now just look sad. Is this the dreaded clematis wilt? If so is it ok to dig them up and plant a new, better quality clematis there or will the disease spread to the new plant?
More likely to be Mildew. Wilt is extremely rare these days.
Lack of water is the usual cause. Give them a good soaking, feed with a liquid feed and spray with a suitable fungicide.