The good news is if you ever find a good place, then you'll fight clematis vines as much as morning glories. I went on a week vacation and returned with the combined weight of new stems from both errant vines overwhelming a 4 1/2 foot Amsonia and a 3 foot brown eyed susan....crashing both to the ground while I was away. I had to tear and rip when I returned...poor things (the plants thugged by the vines).
I'm almost (not quite) ready to just kill the clematis before it totally takes over the bed despite my ripping it out. It's a thirty year old Ernest Markham.

My lucky exposure is south facing with a porch behind it and the house to the west. It's very moist and shady in the bed, but once it climbs onto the porch railings, nearly full sun.

I have heavy clay soil. I lost several clematises until I learned to buy large plants and plant them deep. That did the trick in getting them to survive.

I've also learned that they need to be in full sun. I tried to position them so they would grow up a spruce tree, but it didn't receive enough sun to produce long enough vines to reach the sunny location further up the tree.

As soon as I moved it to a more sunny location, it took off.

I also find it imperative to prune back in March in order to produce a good flush of blooms.

When I moved here late 2005 after my Mom died, I was determined to grow clematis because she always regretted/believed she couldn't. There's a very hardy one growing on my southern boundary that I discovered in 2007 or 2008. I made up my mind to plant them here and there to let them decide where they liked it best. Seems they prefer the northwest side of the house and I now have 3 (not sure of the names) growing & blooming in well-drained, slightly acidic sandy loam. They get only the moisture dished out by Mother Nature. I don't fertilize anything.

Good and loose soil seems to be a common factor here. If I give one another go I'm definitely going to be amending heavily first.

-dig, what do you mean by "plant them deep"? As in bury part of the stems? In a bit of a trench?
CMK

Planting them deep means to plant them a few inches below the surface so that the base of their stems are covered in soil. I actually read that somewhere on this forum 10 or more years ago, and it seems to work for me.

I planted two clematis on my fence a few years ago. They each got dug at by the dogs and cut down by the neighbors. But, today I found them both growing up the fence and blooming! They're not thick with multiple vines yet, but I think we'll get there some day. Mine get mixed morning and early afternoon sun, but are in pretty full sun from 3pm to sunset. Only supplemental water because I was reseeding some lawn this year. We also got generous rains this spring.

Martha

Yes, there is a Clematis forum and it's pretty active :-))

Here's the keys to successful clematis growing:

1) Well draining soil....pH not much of an issue unless out of whack.
2) Large, deep and enriched planting hole. This one of the very few instances where you really want to spend time preparing a deluxe planting hole. The typical recommendation is prepare a 2'x2' planting area (clematis roots can get BIG).
3) Plant deeply -- 2-4 inches deeper than the plant is in the nursery container. This helps to develop additional vines from the root crown with more resistance to clematis wilt (for those varieties susceptible), mechanical damage to the stems and assists with strong root development.
4) Prune back hard in late winter for at least two seasons. This accomplishes similar results to the deep planting. Then prune as suggested for that particular type of clematis.
5) Be patient :-)) Clematis take time to establish well, so allow 3-5 years before you see peak performance. The saying "the first year they sleep. the second year they creep and the third year they leap" was written specifically for this vine!!