Spring 2002's view on the left from the master bedroom window: "Multi Blue" and "Duchess of Edinburgh" near the bottom of the picture, with some new growth Wysteria behind it. In the background you can see another "Duchess of Edinburgh" climbing up the Mountain Ash.
We have three different Clematis cultivars in our yard: Multi Blue, which you see here, Duchess of Edinburgh and an unidentified one which we refer to as Jackmanii but probably is something different with our luck (we didn't keep the packaging:).
Both the Multi Blue and the Duchess of Edinburgh are double flowered: they flower both spring and fall and they both produce sizable flowers that tend to last for quite some time. In 2001 the Jackmanii surprised us by following in the footsteps of the others: it double flowered. We had flowers late spring, it took a bit of a breather and we had another flush of lowers that lasted well into October.
This year the Multi and Duchess seem to be quite a bit later getting on with their second flush of flowers and growth, almost as if they were crowded out by the Wysteria and to that end the Wysteria received a major pruning in mid August: give the Clemmies some more sunshine and room for growth. Spring growth and sunshine are no problem for them since they bud so much earlier than the Wysteria but by July the Wysteria is in a major growth spurt and needs control; more than we have been giving it seems.
Here's an example of the 3 varieties later in the year. You can see lots of seed heads from the spring flowering of the Multi Blue and Duchess of Edinburgh and it is also interesting to note the difference in the size of the blooms of these two; compare the Multi Blue in the picture with the picture of the spring flower version of the same plant in the picture following it.