By Homebird
United Kingdom 
I was concerned that one of my Montana Clematis showed no sign of life, when it's usually full of flower buds by now. I looked around the base of the stem and found it to be covered in a gooey, musous like substance just above soil level. I cut the stem below the affected area and found the stem was rotting and found a yellow grub inside. Does anyone know what this is, and more to the point how to prevent it happening. I haven't a photo to show it. I took one but I can't find it on my laptop or camera.
30 Apr, 2015
Answers
Given that it is C. montana which can be an absolute thug I think there is a fair chance it will grow again. We pruned one of ours drastically in early spring, not necessarily the right time but it had completely got away from us. It is now putting out new shoots with leaves and we will be making sure it doesn't get to be a thug this time.
30 Apr, 2015
The only yellow caterpillar which eats Clematis roots is the larva of the Ghost Swift Moth. Sadly there is no cure. You may be lucky and the plant could well shoot from below ground.
30 Apr, 2015