The causative agent of clematis wilt is wildly disputed. Some claim it is a fungal disease while others say it is a vascular disease that results from too rapid growth caused by overfertilization and the plant wilts to remove the top growth so that the roots can get better established and therefore support the top growth. Many people have had their type II clematis outgrow clematis wilt which tends to support the idea that it is a vascular issue and not caused by a fungal agent. In fact, several studies have been conducted where people whose clematis have supposedly died from clematis wilt were analyzed and no trace of the suspected fungal agent that "supposedly" causes clematis wilt could be found. Therefore there is no reason to think that clippers should be disinfected when cutting back a plant that is suspected of having clematis wilt nor should the plants roots or soil around the plant be drenched with fungicides. Clematis can also wilt due to a myriad of reasons totally unrelated to the proverbial clematis wilt. Lack of moisture combined with low humidity, breaks in stems, rabbits or squirrels nibbling on stems, voles chewing on roots underground, etc. are other possible reasons a clematis can wilt and not be infected with "clematis wilt". My advice is the same as one other poster. Continue to act as if the plant is alive, providing it moisture and fertilizer as needed and I would bet that the plant will resurrect itself, especially if it was planted deeper in the ground than it was in its original pot. This buries dormant nodes that can be called into play should something happen to the top growth. Aliska, pruning group three basically means that each winter or early spring, the clematis stems should be cut back to 2 or 3 nodes above the ground level. A node is the place on the stem where new leaves emerge. This is typically done to clematis that bloom on new wood since the old wood will not produce blooms. This treatment is also recommended for all classes of clematis the first year or two in the ground because it stimulates the production of basal growth at the crown so that you have multiple stems coming out of the ground versus a single stem.

but they don't actually look like the white flies I see on the websites I looked up. These have some green on them and they look like a white mildew but when you touch them, they are actually small flies. They are on the stems only of my beautifully, blooming Jackmani. As everyone probably knows, we've had an unusual amount of rain here in New Hampshire this year. Usually, I get some kind of catepillar that feeds on my Jackmani later in the summer but I've never seen anything like this. Thanks! Any ideas?

I don't think you have anything wrong with your vine. Based on the leaf appearance, rampancy and seeding habits, it sounds like C. terniflora or Sweet Autumn clematis. Considered invasive in many parts of the east, it's a big, aggressively growing vine that benefits from a severe pruning (like down nearly to the ground) annually. The bleaching or discoloring of various sections of leaves and stems is likely due to more exterior vining tendrils simply wrapping around and strangling the others. I wouldn't worry about it. If you cut it back hard next spring and thereafter, I doubt you'll see this problem again.

Many clematis brown out at the bottom as the summer progresses. This is more likely to happen when the plant doesn't get enough water at some point. It continues to grow and bloom. Some people plant other perennials in front to cover the brown leaves. The plant will continue to grow and flower as usual. I was gone over a 10 day period with little rain and came home to find many of my clematis with lower brown leaves this year. I pick off the brown leaves so it isn't so unsightly.