I had a beautiful blooming clematis this July. I was away for a week and came back to no flowers at all and the leaves were been eaten be something. No sign of snails or other insects on the plant at all. I could not see what was eating it. The leaves on the plant at the bottom were a yellowish colour but the top still green. I have seen greenish coloured house flys around it and they do land on it. Could they be eating my plant and if so how do I get rid of them?
If the yellowish leaves turn brown later and entire shoots collapse you will likely have clematis wilt, a chronic problem with large-flowered (hybrid) clematis. This may be spread by slugs and snails. If the yellow leaves turn brown but the rest of the plant remains intact maybe there is a need for more consistent watering or even a nutrient deficiency, either way it might help to mulch with composted manure. If the yellowish leaves are speckled yellow (spotted or stippled) look closely for mites or insects on their undersides.
