I wonder if your fertilizer has a lot of nitrogen in it? Nitrogen pushes more foliage and less flowers. Clematis likes a good soaking no less than once a week. Also let grass and other non-thirsty things grow on the ground to hold water around it, or use quite a bit of mulch but not around the stem.

Cheryl, Hang in there. I've had two for three summers. This is the first time I'm seeing flower buds. I saw them this week. No open blossoms yet. I did give them a mixture of epsom salts and bone meal dissolved in water. We've also had an unusually wet season. Carol- Durham, NC.

chende2292: I decided to monitor a little more closely and started checking every evening when I came home from work. Quite a few buds every day, but they would be gone the next evening. I have started using Sevin (as much as I didn't want to), and still have buds and some are blooming--3! Not much, but still some progress. I have never seen any insects or anything else on it to indicate what is eating the buds. Thanks for your comment!

I have many different kinds of clematis, never had any pest problems, but they need some fertilizer in the spring for sure. I use miracle grow, works every time.

Needs moist feet and sunny top.

This is mainly occurring at the top 1/2 of the trellis. We used to have major issues with rabbits, but with the fox population booming, they are few and far between.