You can't ruin them with fertilizer unless you burn them by not following directions when mixing the fertilizer with water or by over applying it.

There is nothing wrong with that fertilizer. I prefer longer acting granulars myself, rather than fast acting liquids but that is personal preference.

I use tomato food or rose food for my Clems & they seem to do good. Early spring after pruning I give them some bonemeal, along with some rose or tomato food. I fertilize again after each flower flush. I have used some of the Bloom Booster products & also Kelp and all of the different fertilizers work good. You want to stay away from a regular feeding that has high nitrogen. You will get all leaf growth with little flowering. Mamoo

Thanks for all your help.I did the hard prune which I had not done before and used the rose fertilizer. Should be okay as I followed directions.I have never done much with fertilizer but have good soil so they have done well with exception of Huldine. Think maybe I purchased a "lemon" in that one as it disappeared twice last summer.Am seeing some growth comming from the ground so maybe there is still hope.
Lois

Having good soil is the key. Good for you I wish I could say the same. You won't need to fertilize much at all with good soil. You are right to wait on Huldine some times it takes a clematis longer to settle in. It comes down to the root system. If you have a good root system the clematis will come back if hit by any problems. It takes a new young clematis about 3 years for the root system to build up & get strong.