How should clematis be trimmed in the fall in order to get the maximum foliage and flowers in the spring?

You must be careful when you prune clematis, because some of them bloom on old wood produced the previous year. If you cut this wood off you are sacrificing blooms, so I would hesitate to prune in the fall. Wait until the spring, then only do a light pruning to remove dead or weak-looking wood. If you would like some more detailed information on clematis pruning we have good info here at the store.