Karen, good for you, I think. Wait until it takes over everything. I've said in previous posts that I had to move mine twice as it was just oncontrollable and because of my zone, did not get as many flowers as it got too cold. I finally replanted it in a shady, dry spot under an old 50 foot tall blue spruce. It came up, one shoot only, but that shoot is about 10 feet tall and twining around a little wooden fence. It is impossible to kill I have discovered. I will leave it there and hope that it will eventually cover up that space and the propane tank I have there.

Romanticdreamer, my SAC does the exact same thing that yours does and has done so for the entire 5 years it has been in place. My explanation for why the leaves on the interior part of the plant brown out is that the leaves are so hidden from the sunlight as the amount of leaves and vines increases that the ones that are hidden from the sun can't photosynthesize and therefore they die. The problem gets worse as the season progresses and the amount of leaves increases on the top and shades out the interior leaves. It can be rather unsightly but it has never hurt my plant or its ability to bloom. As for the leaves on the backside of your plant, the same could be the reason there. If that side of the plant is in a shady area or is shaded by the increasing size of the plant, that could be the reason. Another possibility is that some clematis don't like the extreme heat and humidity, especially here in the south. Typically, my type II clematis have serious brown out problems once the temps get above 85 degrees. As I said earlier, my SAC has done this interior brown out thing for the five years I have had it, even during years when we have had cooler and wetter weather so I think the most probable cause of your interior brown out is the exterior vines of the plant shading out the interior vines and causing them to die. As for your evergreen clematis, there could be several explanations for one growing better than the other including differing soil fertility in the areas in which they are planted, soil moisture levels, amount of sun one plant gets versus the other, the amount of cold winter wind one plant may be exposed to versus the other, or even just genetic differences in the hardiness of one plant versus the other. You didn't say how long the two plants have been planted so it may just be that one plant got established quicker than the other one. One other possibility is that something is eating the roots of the slower growing plant, not enough to kill the plant but just preventing it from being as robust as the other. See if you can see any visible signs of this. Other than that, providing the smaller one with adequate moisture, mulch, and fertilization are your only alternatives at this time--that and wait and see how the less robust one performs over the long run.

Well, I've spent a fair amount of time fighting honesuckle and multiflora rose to keep it out of the woods on properties I've worked at. Didn't realize until I Googled it that the native wild clematis, VB and Sweet Autumn Clematis were different, and that the non native one was invasive. It's the smelly one I want. The wild clematis is not showy enough to waste space on it in my tiny, tiny, tiny urban downtown row house yard. I don't feel there's much danger of my stuff invading a pristine natural area, the best luck a seed from my yard would have is to land on some vacant urban corner. I haven't read anything about the clematis being a big problem around here, but maybe that's because it is not very commonly grown or sold in nurseries. I don't mind cutting back the upper foliage, to keep it trained along the fence. My neighbors have a grape vine trellis that they have to keep after, but the roots don't wander, just the tops. But after that rose experience, I just don't want something with root suckers, because then I have to go into my neighbors yard to pull the stuff up, and it risks disrupting things, in my yard and hers. I don't want to accidentally uproot her tomatoes or something like that. Maybe I should go with a regular clematis. I sure do LOVE, LOVE the smell of the Sweet Autumn Clematis, and the flowers are pretty too. It smells like baby powder. I have such a tiny yard, I can never decide what to plant, because I am torn between wanting stuff to eat, smell and look pretty. I had to tear out my beloved crab apple which has all three qualities, because it was overrun with rust. I didn't treat it at first because the Cooperative Extension folks said it was just "cosmetic." But eventually the whole thing became infected and distorted and covered with the stuff. And I realized that the soil where all the leaves fell would now be infected for years to come. I finally put the poor thing out of its misery. Now there's a huge hole in my garden and I can't decide what to put there. So far I am replacing the tree with a red ninebark, but I don't know about along the fence behind it and on either side.

Gardengal, yes it is very easy to get seeds from a SAC to germinate. I have had to pull up quite a few seedlings of this plant that resulted from the plant in my garden. The leaves on my plant often develop the slight silver shading that Penn. Pete describes in the early spring, but this coloration always goes away as the season progresses. Just realize that any SAC that comes from seed may vary greatly in scent from the parent plant so if you have a fragrant SAC that you want to duplicate, the only way to insure that the plant you get from the parent will smell the same is to layer your parent plant or get cuttings to root. Seeds from a fragrant SAC may give rise to a seedling that has little to no fragrance.